[HN Gopher] TikTok vs. Douyin: A Security and Privacy Analysis
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       TikTok vs. Douyin: A Security and Privacy Analysis
        
       Author : alanwong
       Score  : 63 points
       Date   : 2021-03-24 09:43 UTC (13 hours ago)
        
 (HTM) web link (citizenlab.ca)
 (TXT) w3m dump (citizenlab.ca)
        
       | resfirestar wrote:
       | > We suspect the "sensitive" field restriction refers to content
       | that is "politically sensitive" but could not confirm.
       | 
       | The other search restricted categories they found (hate speech,
       | limit, suicide prevention) all cause the app to display a
       | predefined message. Rather than "politically sensitive" (which I
       | could see being in the Chinese app but would be weird to have in
       | the global one), this one probably corresponds to another
       | predefined message, specifically "this phrase may be associated
       | with behavior or content that violates our guidelines", which you
       | can get by searching for things like "rape". I don't have the
       | necessary setup to confirm, maybe someone could check.
        
       | psing wrote:
       | I have no idea what most of this means, but I'm glad somebody is
       | doing it.
        
       | zkid18 wrote:
       | Can anyone explain why Google doesn't prevent dynamic code
       | loading on Android? And what in the particular case that can be
       | considered as bad sign?
        
         | tn1 wrote:
         | It's only disallowed by Play Store Policy, not as a technical
         | limitation. Personally, I'm glad that it's not restricted, that
         | way I can still write apps that use it, even if they'll never
         | be officially published anywhere.
        
       | trident5000 wrote:
       | When you give access to TikTok for all of your photos, what
       | exactly do they have the ability to do?...regardless if they are
       | actively doing anything. Can the app selectively download any
       | photo from that moment on in your library? This actually goes for
       | many other apps.
        
         | tn1 wrote:
         | Most smartphones tag photos with useful metadata such as
         | location, which can be mined and sold
        
       | egberts wrote:
       | If TikTok does not access our local-based contact address book,
       | then why does TikTok need access to our contacts?
        
         | yorwba wrote:
         | They say that they didn't see contacts getting uploaded
         | _without permission_.
         | 
         | TikTok's privacy policy contains this paragraph:
         | 
         |  _Your phone and social network contacts, with your permission.
         | If you choose to find other users through your phone contacts,
         | we will access and collect the names and phone numbers and
         | match that information against existing users of the Platform.
         | If you choose to find other users through your social network
         | contacts, we will collect your public profile information as
         | well as names and profiles of your social contacts_
         | 
         | https://www.tiktok.com/legal/privacy-policy?lang=en
        
           | gruez wrote:
           | >They say that they didn't see contacts getting uploaded
           | without permission.
           | 
           | Further down in the report they say it never uploads
           | contacts.
           | 
           | > Neither Douyin nor TikTok (Musically) seemed to upload
           | contact lists, photos, or user files.
        
       | godelski wrote:
       | For those skimming go here for censorship[0]
       | 
       | > The evidence we found is inconclusive in showing if TikTok
       | takes down posts (post censorship) unfavorable to the Chinese
       | government. We found that TikTok contains a code module to handle
       | a special class of server-returned search responses. If the
       | server decides to restrict a search result, it will return a
       | response with zero result item, and indicate the reason for
       | restriction in a special "search_nil_info" field. The client code
       | module contains four predefined reasons for restriction: "hate
       | speech," "limit," "sensitive," and "suicide prevention." The
       | server also sometimes returned reasons that were not predefined;
       | however, we were unable to make sense of their meanings.
       | 
       | [0] https://citizenlab.ca/2021/03/tiktok-vs-douyin-security-
       | priv...
        
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       (page generated 2021-03-24 23:02 UTC)