A recent Reddit thread [1] suggests that FB is able to track location even without the installation of any of their apps. Is this via tracking pixel or through a deal with Samsung/Google?<p>[1] https://www.reddit.com/r/privacy/comments/9z1205/facebook_suggested_that_i_friend_a_person_that_i/?st=JORDJ5U5&sh=ef5fa5aa
My guess? Super easy.<p>You go to Facebook.com from mobile web.<p>Your friend or an acquaintance at a party does too.<p>Both of you are on the same wifi network or a very similar region - maybe one that you visit often or one that you're not normally at (both are interesting for different reasons). You can easily get that from IP or other network characteristics/cookies. Facebook also has your friend graph so they can tell whether you're connected in some way to some Nth degree.<p>That's all it takes.<p>It's probably not some fancy machine learning or AI (though I'm sure that's sprinkled in somewhere to get a confidence level). It's also probably not some evil scheme to trick you into sharing your location.<p>The sheer scale of the network alone is enough for even simple methods to be highly effective and I think that's the crux of what people underestimate and instead gravitate towards conspiracy theories.