[HN Gopher] Look Up Unknown Phone Numbers Using Facebook Reset P...
       ___________________________________________________________________
        
       Look Up Unknown Phone Numbers Using Facebook Reset Password
        
       Author : punkspider
       Score  : 219 points
       Date   : 2021-01-03 20:35 UTC (1 days ago)
        
 (HTM) web link (bytexd.com)
 (TXT) w3m dump (bytexd.com)
        
       | zenincognito wrote:
       | This is gross violation of user privacy but if you file a bug
       | with FB they will say - "won't fix" ; is working as intended.
        
         | wyattpeak wrote:
         | Have they said that? They've previously removed the ability to
         | search for users by phone number, so they recognise the
         | problem.
         | 
         | I can see why someone would have unthinkingly added the profile
         | picture to the recovery screen, but since the downside of
         | resetting the wrong account is so low (an SMS that can be
         | ignored by the rightful user), it seems easily fixable.
        
           | chris_wot wrote:
           | A guy called Brian had his personal contact information
           | (including phone number) plastered all over Facebook's
           | promotional pages.
           | 
           | https://gimletmedia.com/shows/reply-all/76hdrj
           | 
           | I don't think Facebook ever actually apologised for doing
           | this.
        
         | wyxuan wrote:
         | Facebook profile stuff is public info anyway, I don't really
         | see the privacy issue here.
        
           | nrmitchi wrote:
           | Phone numbers that are meant for account recovery and/or two-
           | factor security _only_ are most definitely not public info.
        
             | wyxuan wrote:
             | This method isn't a way of finding out phone numbers from
             | Facebook accounts, so I don't see what you mean here
        
               | MrRiddle wrote:
               | Phone number meant to be private shouldn't be associated
               | with any other info whatsoever.
        
               | wyxuan wrote:
               | Whats the rationale behind this? Outside of prank
               | calling, I don't see what the benefit of having a private
               | phone number.
               | 
               | When I hit someone's voice mail I can get their name, so
               | it's not like most people consider it to be private.
        
               | Aerroon wrote:
               | > _I don 't see what the benefit of having a private
               | phone number._
               | 
               | What's the benefit of having a public phone number? You
               | get more advertisements and spam. With a private phone
               | number only people you've given the number to will call
               | you. You can limit who can bother you.
        
               | throwaway201103 wrote:
               | I don't think this is really true, because spammers call
               | numbers at random (or perhaps, in sequence). They are not
               | working through the published phone book.
        
               | throwaway201103 wrote:
               | Then you probably shouldn't be announcing it in your
               | caller ID when you call random people.
        
               | wyattpeak wrote:
               | Probably not, but does making a person in making one
               | mistake abdicate their right to privacy?
        
       | silver_quiver wrote:
       | I once caught a thief who stole my Nokia MS Windows phone using
       | this feature. Apparently they didn't reset the phone in the
       | start, but put their sim in, and some of their SMS started
       | syncing to my other phone before it occurred to them to reset.
       | One of the message was a Facebook password reset helper message,
       | which had the clear phone number and link to a page which had
       | instructions on how to reset the password. Clicking on that link,
       | also set a cookie IIRC on my laptop, Facebook started showing
       | their DP as one of the options to login (it would still ask for
       | their password so I was not able to log in to their account).
       | Their DP URL has their user ID embedded in it which was enough to
       | find their profile. Turns out they were friend with another
       | person who was in my college (and where my phone was stolen
       | from). We caught that person, involved the university
       | administration, and made him give us the phone back. It was the
       | whole scandal for a while. University expelled that person later
       | on. (Going to police was not really an option since this was in
       | India, I wanted to resolve matter on my own if possible even when
       | I had phone number).
        
       | jokethrowaway wrote:
       | When I still had a social life, Facebook was returning the
       | account simply by searching the phone number or email.
       | 
       | So useful.
       | 
       | I also loved the first release of graph search (not the dumbed
       | down version they released shortly after) which was letting you
       | specify very specific queries. I managed to find a girl I met on
       | a train (whose number I stupidly didn't ask) just with her first
       | name, university and knowing something she liked.
       | 
       | Later on, trying to replace graph search, I had to write some
       | hacky scripts to scrape data across a network of friends (likes,
       | groups, friends, who interacted with you on your public profile +
       | recursively scrape data from friends of friends) to find people.
        
       | rsync wrote:
       | I have a shell script named 'lookup' that lets me know (through
       | twilio) the location, mobile carrier, and registered name of a
       | phone number.
       | 
       | I wrote it to quickly identify mobile vs. non-mobile numbers that
       | I might text - also from the command line.
       | 
       | I won't paste the entire script here (mostly authentication and
       | argument parsing) but the meat of it is:
       | /usr/local/bin/curl -X GET "https://lookups.twilio.com/v1/PhoneNu
       | mbers/$number?Type=carrier&Type=caller-name" -u
       | $accountsid:$authtoken
       | 
       | I use this several times weekly.
       | 
       | EDIT: by "location" I mean their mobile country code - not their
       | actual location which, of course, you cannot get without
       | (ab)using SS7 which is beyond the scope of twilio ...
        
         | fy20 wrote:
         | In countries which have number portability this may not always
         | be right. For example my phone number returns Vodafone, which
         | was the carrier it was originally assigned to 15 years ago, but
         | I've been on other networks for over a decade.
        
           | usr1106 wrote:
           | When Finland got number portability some 15 years ago it also
           | got a free look-up service to see the real operator of every
           | number. This was required for price transparency. Calling
           | within your own network can be cheaper than to a competitor
           | and you should be able to know so before making the call.
           | 
           | Not sure how other countries have handled that. The US had
           | the different approach, callee pays for the mobile part.
           | 
           | Have not looked into the issue for a decade...
        
         | Merman_Mike wrote:
         | What does a few lookups a week cost you? Just a few cents per?
        
           | janzer wrote:
           | According to https://www.twilio.com/lookup 1.5 cents per
           | lookup, would be 1 cent without the carrier information.
        
             | Merman_Mike wrote:
             | Thanks. I've wanted to do this. Didn't know if there was
             | some account overhead or other fees.
        
         | hadrien01 wrote:
         | Where do they get the names from?
        
           | mct wrote:
           | CallerID information. There are a bunch of lookup services
           | available for it: https://www.voip-info.org/cnam/
        
       | scottmcdot wrote:
       | Sometimes people will change their Facebook name to be more
       | anonymous however their Facebook url stil has their full name on
       | it.
        
         | TeMPOraL wrote:
         | It's funny to see, but I guess it works against non-tech-savvy
         | people.
         | 
         | Not sure if that's still the case, but Facebook used to leak
         | one's maiden name via URL for people who changed their surname
         | after getting married.
        
       | actuator wrote:
       | This doesn't seem like something which is of concern but on a
       | tangential note, I wanted to check how you guys maintain your
       | phone number privacy. Consider the cases:
       | 
       | - I absolutely hate giving phone number to new ecommerce sites as
       | it is just a database that will eventually get leaked. The only
       | one I can trust here is Amazon probably.
       | 
       | - Phone number on packages. A person can read your name, address
       | and phone number from a package which seems like a lot of info.
       | Address is required but phone number shouldn't be as you can very
       | well redirect the call using custom pins.
       | 
       | - Talking to new people on dating apps. I don't use IG, so phone
       | number is something I have to exchange. Now I would never give my
       | number to an anon on internet but on dating apps I have to for my
       | own benefit.
       | 
       | Do you guys maintain burner phone numbers for these cases?
        
         | vmception wrote:
         | I maintain dual sims in my iphone. For dates this means that my
         | "burner number" also has blue text messages, revealing to them
         | it is an iphone and that other features are available like
         | facetime and airdrop in the future.
         | 
         | I also maintain google voice numbers to set up additional
         | accounts on places and more easily filter spam.
         | 
         | Right now, my one device has three numbers on it. (2x sim, 1x
         | google voice).
        
           | bartvk wrote:
           | > I maintain dual sims in my iphone
           | 
           | That's a very good idea, thanks for this.
        
           | actuator wrote:
           | I need to upgrade my Pixel 2 to a dual sim phone too. I think
           | this seems like the easiest way. Not sure how WhatsApp etc
           | support dual sim though.
        
             | vmception wrote:
             | WhatsApp is the only one that makes it inconvenient.
             | Perhaps Signal is one identity too, and therefore less
             | convenient.
             | 
             | But you can always at the very least set up the accounts,
             | using your browser on a PC.
             | 
             | You just won't get chat notifications for multiple numbers
             | on one device.
             | 
             | Telegram app lets you have 3 accounts logged in, the only
             | similarity being that setting up a Telegram account
             | requires phone number authentication. But the similarity
             | ends because a Telegram account on your device doesn't need
             | to be linked with a phone number accessible from your
             | device.
        
               | actuator wrote:
               | I think the problem of going outside prevalent apps like
               | Text/iMessage/WhatsApp is that not everyone will have the
               | less prevalent ones.
               | 
               | Few people have Telegram, Signal seems like a very niche
               | tech/journalist thing.
        
               | vmception wrote:
               | Thats just informative for you.
               | 
               | I'm not really focusing on the dating use case and have
               | already solved that for myself, and for you, and I'm not
               | sure why you are overthinking it aside from your upcoming
               | expensive of buying a new phone and additional cellular
               | plan. The practicality is already there.
        
             | philposting wrote:
             | You can install WhatsApp and WhatsApp Business, with a
             | number on each. WhatsApp business has some extra functions
             | for businesses, but is otherwise the same.
        
               | actuator wrote:
               | It does show you are texting with a business account
               | which might just seem weird to the other person. If they
               | didn't find not having IG shady before, I am sure they
               | will now.
        
               | vmception wrote:
               | You're overthinking this.
               | 
               | I'm aware of people that immediately ask for social
               | media, and rationalize it with trying to disprove
               | infidelity or an assurance they wont get murdered, I can
               | tell you that most people I've dated over the past two
               | years did not ask for that. At this point I think there
               | is a level of maturity involved in not asking questions
               | you don't really want the answer to, as they too would
               | prefer not to lead with their social media.
               | 
               | Its pretty much the same as introducing a date to your
               | friends. You don't typically lead with that. YMMV.
        
         | gorgoiler wrote:
         | For commerce I use an SMS to email gateway and automatically
         | file those emails into a separate mailbox.
         | 
         | It started attracting spam after about a year. I found that I
         | never need to be alerted about anything via SMS though.
         | 
         | The only time I use it is when I know I should have just
         | received a message, which is at the top of the inbox above all
         | this week's spam.
         | 
         | I'm quite aware that I'm side stepping a lot of two factor
         | policies by doing this. (My phone mail client can read all my
         | email accounts.) One has to be careful not to do anything silly
         | and I'm glad GitHub steered away from SMS 2FAC.
        
       | Magicstatic wrote:
       | Is this a security problem? Depends on who you ask - but I'm
       | willing to bet it would fall into the "accepted risk" category
       | for the Facebook security team if they had to evaluate this.
       | 
       | The reality is that phone number lookup services are available
       | all over the web which provide even more information (first+last
       | name, address, zip code, social media profile links, etc etc etc)
       | for free (https://www.bestfreephonelookup.com/phone-number/ as an
       | example) - these services get their info from data aggregators
       | and usually - your carrier! I don't see how Facebook exposing (in
       | _limited_, very specific circumstances) the first name of a
       | persons phone number being a security issue.
       | 
       | All the people in this thread screaming GDPR violation don't
       | understand that if someone decides to stop using Facebook and
       | delete their account, this method to lookup someone will not
       | work. Sidenote: If you're really paranoid about having your phone
       | number expose your real name when you're using any type of
       | service online, just sign up for a Google Voice
       | (voice.google.com) account and link it to your cell phone - I use
       | this whenever I sign up for anything online and it saves me a ton
       | of spam and scam calls.
       | 
       | EDIT: Facebook removed the ability to use the in-app search box
       | in Facebook to find people based on just a phone number, this has
       | been removed for at least 2 years.
        
       | Jon_Lowtek wrote:
       | So called "Identity Graph" or "Identity Resolution" providers
       | integrate with thousands of CRM systems and harvest the customer
       | data in bulk, then sell the combined profiles back to the
       | companies integrating them. Get an API access, provide one piece,
       | like a phone number, and they resolve it to names, home
       | addresses, email addresses, social media usernames and so on.
       | 
       | I mean i don't like facebook, but this topic is small fish
        
       | tomp wrote:
       | Or you could just do a search _on_ Facebook?!
       | 
       | I don't know if it still works, but some time ago I used that to
       | find the real name of someone just using their phone number.
       | However, that person wasn't really _trying_ to keep their
       | identity secret.
        
       | ChrisMarshallNY wrote:
       | Those will work (maybe), but their usefulness is limited, as just
       | about every bad call I get, is spoofed.
       | 
       | I have a canned response txt, that I send, when declining the
       | call.
       | 
       | I often get "message failed to send," but I sometimes get a
       | confused text from someone, telling me they didn't call.
        
         | Igelau wrote:
         | TFA is terribly irresponsible advice due to how many calls are
         | spoofed. I don't need someone tracking me down and raining
         | hellfire down on me over a spoofed number that happened to be
         | mine.
        
       | eyeareque wrote:
       | I once tracked down a Craigslist scammer by looking up their
       | phone number (it was a groove number) within google voice. It
       | showed his name, google profile, and photo. Their name helped me
       | find their Facebook and Instagram. Long story short, I got my
       | money back.
       | 
       | Iirc: Google used to enable allowing people to look you up by
       | your phone number (it was something along the lines of: help your
       | friends find your account). This used to be on by default, it
       | doesn't seem to be anymore.
       | 
       | Try looking up your friend's google voice numbers in google voice
       | and see if they have the option enabled.
        
       | awinter-py wrote:
       | password reset flows are generally a privacy leak
       | 
       | if you use email as some kind of account key, you can generally
       | find out _whether_ that email has signed up (if not the username)
       | 
       | automatic password reset and email verification are good for
       | businesses and users in a lot of ways so this is a tradeoff
       | 
       | if FB is showing the _specific_ account linked to an SMS that 's
       | IMO negligent but shrug, they employ more lawyers than I do and
       | they've never been investigated by the FTC for privacy issues
        
         | evan_ wrote:
         | In most cases attackers can use the signup flow to see if an
         | email is registered so as long as it isn't _less_ protected
         | (with a captcha etc) it isn't any more of a privacy leak in
         | that regard.
        
         | Buge wrote:
         | Are you being sarcastic about the FTC?
         | 
         | https://www.ftc.gov/news-events/press-releases/2019/07/ftc-i...
        
           | awinter-py wrote:
           | oh yeah other than the one time. but if they had done
           | anything really bad there would have been some kind of 5
           | billion dollar for the deceptive disclosure and settings and
           | some kind of toothless compliance council involving the board
           | of directors
        
         | 52-6F-62 wrote:
         | I've seen this obfuscated by some systems by always just
         | throwing the user a message saying the reset email has been
         | sent so that there's no indication whether or not the email is
         | associated with an account or not.
         | 
         | Of course, that doesn't help someone who can't remember if
         | they'd signed up or not but it's probably the safer way to go
         | in general.
        
           | awinter-py wrote:
           | yup, need to do it in the signup case as well but it solves
           | the problem
        
           | contravariant wrote:
           | There's typically a system that forbids you from adding an
           | additional account with the same email though.
        
         | MattGaiser wrote:
         | Can't you just say that a password reset email has been sent?
         | That is what we did when I worked in banking as a way to
         | prevent this.
         | 
         | Whether or not you have an account, the system says a reset
         | email has been sent.
        
           | zwog wrote:
           | In most cases you can find out whether an account with a
           | specific email address exists by trying to sign up with it,
           | though.
        
             | MattGaiser wrote:
             | Fair. We didn't have that issue because you don't sign up
             | for bank accounts online.
        
           | dasb wrote:
           | But then you confuse legitimate users that don't remember
           | what email they signed up with.
        
             | smichel17 wrote:
             | I why not actually always send an email to that address? If
             | the email isn't registered, change the message to suggest
             | that perhaps they signed up with a different email, or
             | they'd like to sign up instead?
        
           | kfarr wrote:
           | Yes this is the correct answer. I've seen some systems
           | respond with "if there's an account registered to this email
           | address you will receive a password reset email" whether or
           | not the address is registered
        
       | kristopolous wrote:
       | Y'all know we used to publish everybody's phone number in a book
       | along with their address and then distribute copies to every
       | household, right?
       | 
       | We did it for many decades and it was fine. Every pay phone,
       | which was a phone anyone with a couple coins could make anonymous
       | calls from, had this giant book right there for your reference.
       | Everyone knows this, right?
       | 
       | If you didn't know someone's number you could look it up and call
       | them. They wouldn't have caller ID so you'd identify yourself and
       | then you could talk to them.
       | 
       | This was 99.99% of the time not a problem.
       | 
       | We need to stop freaking out about a "security vulnerability"
       | that does 1/50th of a system that everyone used mostly without
       | incident for decades.
       | 
       | Besides, none of this information is actually private now, it's
       | all still for sale. These companies freak out about this stuff
       | because your data is their product, it's not supposed to be free.
        
         | Hamuko wrote:
         | > _Y 'all know we used to publish everybody's phone number in a
         | book along with their address and then distribute copies to
         | every household, right?_
         | 
         | And we didn't use to tie second-factor authentication into SMS
         | messages to your phone number.
        
           | taneq wrote:
           | We didn't used to have two-factor authentication at all for
           | most things though.
        
           | thesuitonym wrote:
           | You're not supposed to do that today, either.
        
         | lolsal wrote:
         | Ok, but you could opt out of the phone book. You know about
         | unlisted numbers, right?
        
         | framecowbird wrote:
         | One key difference is that, at least in the UK, you could opt
         | out
        
           | DanBC wrote:
           | And also in the UK when someone tried to issue a reverse
           | look-up CD they were sued by whatever BT was called at the
           | time.
        
           | YetAnotherNick wrote:
           | Even from facebook you could opt out. I am mostly sure you
           | can create account without phone number
        
             | cfjgvjh wrote:
             | It might depend on your IP and other factors. I tried to
             | make a new one about a year ago and could not do it without
             | phone verification.
             | 
             | Maybe they'll let you sign up without a phone number via
             | Tor or something though.
             | 
             | It's not just Facebook that requires a phone verification
             | now, I can't even make a Google or Yahoo Japan account
             | without it. At least on these services you can "reuse"
             | previously used numbers by unlinking them, at least a few
             | times. But services like Discord lets you verify with each
             | number once and only once as far as I know.
             | 
             | On the one hand I get that there's a room for abuse by
             | spams, but on the other hand, I really wish I could freely
             | sign up to services.
        
               | c22 wrote:
               | I have an old Facebook account without a phone number
               | linked to it. Every time I log on they badger me to link
               | a phone number. Recently the field is pre-filled with a
               | phone number I use that I never explicitly gave them...
               | 
               | If it is possible to make a new account without a number
               | I am assuming it is not made easy.
        
               | colejohnson66 wrote:
               | Is that "pre filled" number your browser's auto fill by
               | chance?
        
           | jofaz wrote:
           | You could opt out in the US too, required paying a monthly
           | unlisted number fee
        
         | goatcode wrote:
         | Did you have one of those books that was organized by number,
         | instead of name? I didn't.
        
         | cik wrote:
         | Part of the issue is the meaning of privacy now. Decades were
         | spent fighting for the right to not receive, or to receive
         | targeted phone calls.
         | 
         | We're now (at least my cohort) in a world where no one, ever
         | answers the phone. Either you're in my phone book, or I'm never
         | answering the phone. It's rather liberating.
        
           | kristopolous wrote:
           | That's only because calling is the new fax. Would you ignore
           | an SMS from an unknown number? Let's say the content was
           | "Hey, how've you been? It's been a while!"
        
             | cik wrote:
             | Actually yes. I ignore all SMSes. WhatsApp is the go-to
             | communication method in Israel. SMS is only for government
             | services and a company from whom I've ordered from in the
             | past.
             | 
             | I get zero advertising now that I moved. It's liberating.
        
               | NikolaeVarius wrote:
               | Relying on Facebook for communication. Horrifying.
        
             | kevin_thibedeau wrote:
             | Yes they get ignored because that's the entry point for
             | scammers building lists of active numbers. Same as one
             | should mute but not disconnect spam voice calls as that
             | gives them info about your presence.
        
               | colejohnson66 wrote:
               | I've heard this "active number" and "active email" thing
               | for a while, but isn't the fact that the message wasn't
               | "returned" undeliverable a sign already? If I send an
               | email to a GMail account that doesn't exist, Google will
               | reply that the account doesn't exist. It's the same with
               | calling (every carrier) and texting (at least with AT&T;
               | I just tested it)
        
             | oauea wrote:
             | At _most_ I might send back a  "Who is this?", but yes, I'd
             | probably ignore it if it wasn't signed by a familiar name.
        
           | TeMPOraL wrote:
           | That's not really a privacy issue, though. That's _marketing
           | issue_. That is, we let marketers destroy phones as a medium
           | of communication. The answer to that isn 't to legislate
           | hiding your phone number. The answer to that should be to
           | _legislate this type of marketing away_.
           | 
           | Advertising is cancer, and I'm constantly surprised by the
           | ends to which people go to justify its continued existence.
        
             | throwaway2245 wrote:
             | Legislating away cold-call marketing is already done; it
             | hasn't stopped it from happening, since it's almost
             | impossible to trace the culprit.
        
               | TeMPOraL wrote:
               | US until very recently wasn't even trying. EU is, and our
               | phones are quite usable. Things could be improved - I
               | wish there was a way to get rid of the few marketers that
               | find their ways to skirt the regulatory boundary. It
               | doesn't seem impossible to achieve.
        
         | talonx wrote:
         | While this is factually correct, what you are missing is the
         | point that most people have mobile phones these days, and their
         | phone numbers are tied to a ton of other accounts and services.
         | These include second factor auths (using text or voice calls)
         | for other websites, bank accounts, social security ids (I'm not
         | talking about the US), insurance policies - the list goes on.
         | You would not want your number to be available to the general
         | public - because that makes you vulnerable to social
         | engineering attacks.
        
           | usr1106 wrote:
           | Here in Finland many if not most mobile phone numbers are in
           | the phone book. Well, no physical book has been printed for
           | years, but you can call directory enquiries or look them up
           | online. Even reverse look-ups are possible. (Only an ever
           | shrinking minority of households still owns a landline.)
           | 
           | How exactly would that subvert 2FA via SMS? Except for
           | calling and ask please read the SMS you just received for me.
           | While that will work with some people, I am not worried in my
           | case.
        
             | anonymousiam wrote:
             | It subverts 2FA and SMS because of SIM hijacking. If a bad
             | actor has your mobile number and you use that for 2FA, they
             | can socially engineer (or bribe) a rep from your mobile
             | company to assign your number to a new SIM/phone.
             | 
             | This is a common attack these days.
             | 
             | https://www.theverge.com/2019/5/11/18564381/community-
             | hackin...
        
               | fckthisguy wrote:
               | To elaborate how easy this is:
               | 
               | I did this recently in my own number after loosing the
               | sim card. I just called up the phone company and
               | convinced the customer service agent to assign the number
               | to a new sim card I had just bought from the petrol
               | station near my house.
               | 
               | I provided no authentication for this and they had no way
               | to prove I was the owner of the account.
               | 
               | Took all of 5 minutes to pull off.
        
         | rendx wrote:
         | The phone book was always opt-in in Germany, and reverse lookup
         | was declared illegal after some time too. They suggested in
         | when you signed the contract, but it was a clause you could
         | easily not accept, at no extra cost.
        
         | codingdave wrote:
         | There was also opt-out, even decades ago. You could tell the
         | phone company that you wanted an unlisted number, and you would
         | be excluded from the phone book.
        
           | thesuitonym wrote:
           | You can do that with Facebook, too. In fact, Facebook does
           | not know and has never known my phone number.
           | 
           | Or rather, I'm sure it does know because my friends have me
           | in their contact lists and shared that with Facebook, but
           | it's not tied to my account in any UI way. I didn't have to
           | opt out because I never even opted in.
        
         | aembleton wrote:
         | Could I easily look up a name for a given phone number with
         | this book?
         | 
         | Or did I have to go through the whole book to find a match?
        
           | kristopolous wrote:
           | Of course. It was called the greypages.
           | https://en.wikipedia.org/wiki/Reverse_telephone_directory
           | 
           | In old movies you sometimes see people ask the operator to do
           | a reverse search as well so I assume it wasn't a big deal.
        
         | richrichardsson wrote:
         | Attitudes have changed. A friend recently posted a newspaper
         | clipping from nearly 40 years ago when he won some sort of
         | "attractive baby" competition in Guildford, UK. The paper
         | included his name and full address. Can you imagine that now
         | and the "BUT WHAT ABOUT THE PEDOS!" response it would illicit!
        
         | wwwwewwww wrote:
         | I'm sure not everyone knows this, because there are are people
         | on this site who have not grown up with phone books.
         | 
         | The article talks about a reverse phone book: according to the
         | author, given a phone number, you are able to look up name (and
         | profile picture). To my understanding there were no reverse-
         | lookup phone books like that back in the day.
        
           | lb1lf wrote:
           | -In the good old days (sixties, presumably also earlier)
           | police forces in at least some countries had phone books
           | sorted both by address and by number.
           | 
           | (Source - flea market find, a Norwegian book on the state of
           | the art in criminology, published c. 1965)
           | 
           | Edit: Oh, I just remembered that locally, the athletic union
           | published a phone book with all subscribers in the
           | municipality listed by number.
           | 
           | This was c.1990 - after call ID was an option if you bought a
           | decoder (or was an ISDN subscriber), before Internet phone
           | directories were a thing.
        
             | [deleted]
        
           | Jestar342 wrote:
           | Well given the phone book was a list of names, addresses,
           | _and numbers_ you could, in fact, do reverse lookups.
        
             | dbbk wrote:
             | The point is it was ordered by name, not by number. So you
             | can't jump to an arbitrary number.
        
           | bonzini wrote:
           | In some countries you could call a number to do it.
        
           | Triv888 wrote:
           | There was, you could buy a disc that contained the book and
           | do a search.
        
           | mmcgaha wrote:
           | Here is an example on ebay of a book that has an index by
           | phone number and even an index by street address.
           | 
           | https://www.ebay.com/itm/Vintage-Phonebook-1987-LAS-
           | CRUCES-N...
        
         | Rygian wrote:
         | I get it that the right to privacy has not been such a priority
         | in the past, especially outside Europe, but there's nothing
         | wrong in trying to strengthen it.
         | 
         | What was maybe fine a couple decades ago is no longer fine in a
         | world where anyone from any jurisdiction in the world can abuse
         | your privacy for fun and profit.
        
           | kristopolous wrote:
           | 30 years ago things were far more ripe for fraud and abuse.
           | Things couldn't be verified in the slightest.
           | 
           | In the 1800s a famous fraudster invented an entirely
           | fictitious country and then sold fraudulent land grants and
           | bonds for it - really,
           | https://en.wikipedia.org/wiki/Gregor_MacGregor
           | 
           | There's a reason why the most famous confidence tricks have
           | names that go back hundreds of years (eg, spanish prisoner)
           | and there's fun named people like Soapy Smith that mastered
           | things like mock auctions
           | https://en.wikipedia.org/wiki/Soapy_Smith or "Kid Dropper"
           | named after his love of the "drop swindle" scam:
           | https://en.wikipedia.org/wiki/Nathan_Kaplan
           | 
           | Charles Ponzi did his stuff 100 years ago and he just lifted
           | it from earlier con artists like Adele Spitzeder
           | https://en.wikipedia.org/wiki/Adele_Spitzeder
           | 
           | The idea that we need to "lockdown" things because we live in
           | unprecedented times relies on someone not really reading any
           | history. Things are relatively pretty safe these days.
        
             | debaserab2 wrote:
             | The fact that these risks existed a century ago is a poor
             | argument for suggesting they shouldn't be taken seriously
             | in the present.
             | 
             | We live in an era where things can be done instantly online
             | with sufficient information. A sophisticated conman from
             | the 1800's can now execute fraud in seconds instead of
             | plotting for weeks, and they can do so in an automated
             | fashion. The risk isn't anywhere near the same.
             | 
             | A white pages phone book hooked up to pay phone is bound to
             | the region in which it is distributed. A bug on a website
             | that links phone number to full name is exposed on a global
             | scale. Not to mention, a landline number is not anything
             | like a mobile phone number, which is a unique identifier to
             | tons of PII.
        
               | kristopolous wrote:
               | Right but if I presented this problem to you without
               | using the word "phone" I'm pretty sure the answer would
               | be "throttle and rate limit" and ban for abuse, not kill
               | off the feature.
               | 
               | These lists are still available for purchase and thus
               | they are still available. I'm not a criminal so I don't
               | know what websites to go to but I'd be shocked if a file
               | with a name like "US-ATT-SUBSCRIBERS-2020-12.sql.gz"
               | doesn't exist.
               | 
               | As an example, my friends pool together as a "family
               | plan" and we get a discount. I frequently get texts and
               | calls from people asking for the person who pays the
               | account. I don't use their name in anything I sign up for
               | and they don't use my number. We don't even live at the
               | same address - the phone bill is literally the only paper
               | trail that connects us.
               | 
               | Therefore, the only way this mistake is possible is if
               | these marketers bought the subscriber list or found a
               | copy online somewhere.
        
         | throwaway2245 wrote:
         | > Y'all know we used to publish everybody's phone number in a
         | book along with their address and then distribute copies to
         | every household, right?
         | 
         | By _user choice_. You had to register your phone number and
         | address to be in that book.
         | 
         | It was immediately obvious to everyone what was going on:
         | everybody received the same complete book of information and
         | knew how that was published, with at least a system of opting-
         | out (it was always opt-in, from what I remember).
        
           | eli wrote:
           | No, it was opt out. You had to pay _not_ to be listed.
        
             | throwaway2245 wrote:
             | That depends on when and where.
             | 
             | Like I said, phone books were evident to everyone because
             | they saw the consequence. That's not a good comparison
             | here.
        
       | [deleted]
        
       | georgiecasey wrote:
       | This was great in my single days to look up random numbers you'd
       | taken down in your phone after a night of drinking
        
       | blue_box wrote:
       | This is a GDPR violation. I hope the author already complained to
       | the authorities. (Since there is a German phone number is used in
       | the example, I assume that the authors is from Germany)
        
         | rendx wrote:
         | I don't understand why this was downvoted. It _is_ a GDPR
         | violation. That 's a fact.
        
         | [deleted]
        
       | searchableguy wrote:
       | You can also use one of spam blocking spyware apps.
       | 
       | https://www.truecaller.com/
        
       | kumarvvr wrote:
       | I think the whatsapp profile doesnt work until the other party
       | messages you or gives you a reply.
        
         | zwog wrote:
         | It depends on the user's privacy settings. You can set who can
         | see the profile photo: everyone, your contacts or no one.
         | 
         | But I don't know what is the default setting.
        
         | bamboleo wrote:
         | It depends on their settings. I usually can see photo and name
         | as soon as I add them. For my own number however people can't
         | see either piece of information until I add the number to my
         | contacts.
        
       | teekert wrote:
       | I do this all the time: Don't recognize number, add to contacts,
       | check Whatsapp picture. Doing this I found out an old aunt I
       | hadn't talked to in a long time was pocket calling me recently :)
        
       | jomaorfe wrote:
       | Nobody ever got fired for buying IBM.
        
       | jsnell wrote:
       | Before gathering up the mob and handing out the torches and
       | pitchforks, you should probably establish what the facts actually
       | are. I don't think the author of this post has really done that.
       | 
       | The way these systems should work, and appear to work in
       | Facebook's case, is that the amount of information revealed
       | depends on risk analysis.
       | 
       | For example, I just tried recovery from an IP I've used Facebook
       | from, and from a fresh IP from a low reputation hosting provider
       | located in a country unrelated to the account. The first case
       | reveals the user's name, but that's pretty reasonable since the
       | request has a decent amount of affinity for the account. The
       | risky looking recovey does _not_ reveal the name,
       | 
       | Both logins show the first letter of the local part of the email
       | address, which is basically no information leakage at all.
       | (Though honestly, if you show just one letter even for non-risky
       | recovery attempts, why bother? It can't possibly be of any
       | significant help to the users.)
       | 
       | I can't tell whether the profile picture changes based on the
       | risk analysis outcome or not, since I don't have a test account
       | with one.
       | 
       | (It's still possible that this is a bad implementation; e.g. if
       | it were to be revealing my username for any recovery attempt from
       | the correct country, that'd be unreasonable since it's trivial to
       | figure out the country from the phone number. But even so one
       | should still establish what the relevant parameters are, so that
       | we can figure out whether the behavior is reasonable.)
        
         | lolsal wrote:
         | > (Though honestly, if you show just one letter even for non-
         | risky recovery attempts, why bother? It can't possibly be of
         | any significant help to the users.)
         | 
         | Why? I use multiple email addresses and on these occasions
         | seeing that single letter (at beginning or end) helps me know
         | which account to check for recovery steps. This is significant
         | to me.
        
         | cassianoleal wrote:
         | > if you show just one letter even for non-risky recovery
         | attempts, why bother? It can't possibly be of any significant
         | help to the users.
         | 
         | It's of much help to me.
         | 
         | I use different email addresses for different services, and any
         | help the service can give me to ensure I'm giving it the right
         | email I use on it is helpful.
        
         | dn3500 wrote:
         | It actually says right there on the screenshot "You can see
         | your name and profile picture because you're using a computer
         | network you've logged in on before." So this is only working
         | because the author has used this computer (or one on the same
         | subnet) to log in to his FB account before (private browsing
         | mode does not obscure the IP address). It will not work in the
         | general case.
        
           | epmaybe wrote:
           | Are large organization subnets sufficiently masked that this
           | would not work? For example, a university network.
        
             | pcthrowaway wrote:
             | If not, you could possibly use the domain facebook displays
             | for the recovery email (for example x __ __@cornell.edu) to
             | direct you to the network you need to retry from
        
               | jsnell wrote:
               | Facebook does not reveal even a single letter of the
               | recovery email's domain.
        
         | kuroguro wrote:
         | The author is a bit late to the party - this used to be a
         | thing. IIRC you could just enter the phone in fb search and it
         | would spit out the name + fb link even for private profiles.
         | 
         | Someone I knew scanned down a whole country's numbers in a
         | couple of months (there was some rate limiting and that's about
         | it) - and that guy just did it for fun. I'm sure there were
         | plenty of shady companies doing the same thing.
         | 
         | After a while FB started cracking down on this. They even
         | admitted they knew about it for years. Can't find a link but
         | IIRC that was 4-5 years ago.
        
           | Macuyiko wrote:
           | You're right. I just looked up the time frame: in 2017, I did
           | the same thing. It was widely known about and FB took way too
           | long to fix it.
        
       | scotty79 wrote:
       | Tried this with my friends phone number. Facebook didn't show her
       | picture or name. Just first letter of the email.
        
         | dheera wrote:
         | I don't post my real phone number on Facebook, and I don't know
         | why anyone would.
        
           | thatguy0900 wrote:
           | If anyone with you as a contact uses Facebook then Facebook
           | probably knows it anyway
        
             | Buge wrote:
             | They probably know it in some database, but won't let you
             | log in with it. So this password recovery thing won't work
             | on dheera.
        
             | dheera wrote:
             | Most people I know don't have me as a phone contact either,
             | typically just e-mail and Facebook or WeChat, but not
             | phone.
             | 
             | I don't use phone calls much, and I block all unscheduled
             | calls anyway.
        
       | hulahoof wrote:
       | A number of years ago I trialled a reverse look-up using this
       | method (for both mobile numbers and email) as a grey hat project
       | for a data aggregator I contracted to validate existing email /
       | phone pairings (bad email and numbers gets you banned quickly by
       | dispatch partners).
       | 
       | It worked because the returned "is this you" image at the time
       | returned a filename that was a base64 encoding of the users ID
       | for the graph interface, which at the time pulled back a
       | surprising amount of info if you query the key directly
       | (obtaining the key generally required you to be a friend-of-
       | friend or closer).
       | 
       | I got hit rates of about 70% for a sample of ~100,000
       | email/mobile pairs (that were already suspected to be valid).
       | 
       | Sounds like the trick to get the key has been resolved (I was too
       | early in my career to feel comfortable disclosing my research)
       | but I am surprised a similar vector exists almost a decade on -
       | especially after the whole Cambridge Analytica fiasco.
        
       ___________________________________________________________________
       (page generated 2021-01-04 23:03 UTC)