[HN Gopher] Websites Are Tracking You via Browser Fingerprinting
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       Websites Are Tracking You via Browser Fingerprinting
        
       Author : gnabgib
       Score  : 11 points
       Date   : 2025-06-18 20:55 UTC (2 hours ago)
        
 (HTM) web link (engineering.tamu.edu)
 (TXT) w3m dump (engineering.tamu.edu)
        
       | halb wrote:
       | This is a problem because unlike cookies, that are tied to
       | specific domains and isolated by security boundaries,
       | fingerprints can be computed across any domain. It's easy to
       | imagine how a website that tracks users and serves ads solely
       | using fingerprints could be exploited to gain informations about
       | a victim, simply by collecting their fingerprint.
        
       | legitster wrote:
       | As someone who works in this tech space, nobody brings up how
       | long fingerprints persist. And the reality is that even a really
       | precise fingerprint has a half-life of only a few days
       | (especially if it's based on characteristics like window size or
       | software versions).
       | 
       | A lot of the big ad networks right now instead rely heavily on
       | geo-data. Which is why you are probably seeing lots of ads in
       | your feeds that seemingly cross between devices or are relating
       | to interests of your spouse/friends/etc. They just look at the
       | geo on your IP and literally flood the zone.
       | 
       | > They developed a measurement framework called FPTrace, which
       | assesses fingerprinting-based user tracking by analyzing how ad
       | systems respond to changes in browser fingerprints.
       | 
       | I'm curious to know a bit more about their methodology. It's more
       | likely to me that the ad networks are probably segmenting the ads
       | based on device settings more than they are individually
       | targeting based on fingerprints. For example, someone running new
       | software versions on new hardware might be lumped into a hotter
       | buyer category. Also, simple things like time of day have huge
       | impacts on ad bidding, so knowing how they controlled would be
       | everything.
        
       | leptons wrote:
       | _"Fingerprinting has always been a concern in the privacy
       | community, but until now, we had no hard proof that it was
       | actually being used to track users,"_
       | 
       | Huh? In 2025?? Fingerprinting has been around and actively used
       | to track users for probably at least 20 years.
        
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       (page generated 2025-06-18 23:00 UTC)