> Why do they need to know my screen brightness, memory amount, current volume and if I'm wearing headphones?
This is clearly adding entropy to de-anonymize users between apps, rather than to add specificity to ad bids.
replies(9):
This is clearly adding entropy to de-anonymize users between apps, rather than to add specificity to ad bids.
Everyone would need to be generating the same 'random noise' for any such tactics to be truly effective.
Here's a real-life example: You show up alone at the airport with a full-face mask and gray coveralls. You are perfectly hidden. But you are the only such hidden person, and there is still old cam footage of you in the airport parking lot, putting on the clothes. The surveillance team can let you act anonymous all you want. They still know who you are, because your disguise IS the unique fingerprint.
Now the scenario you're shooting for here is:
10 people are now walking around the airport in full-face masks and gray coveralls. You think, "well now they DO NOT know if it's ME, or some terrorist, or some random other guy from HN!"
But really, they still have this super-specific fingerprint (there are still less than 1 person in a million with this disguise) and all they need is ONE identifying characteristic (you're taller than the other masked people, maybe) to know who's who.
They didn't need to adjust their system one bit.
Your analogy applies more to things like trying to anonymize your traffic with Tor, where using such an anonymizer flags your IP as doing something weird vs other users. I’m not convinced simply fuzzing the values would be detectable, assuming you pick values that other real users could pick.
These are professional networks with a ton of capital thrown behind them. They have pretty decent algorithms, heuristics, etc; and you don't make money (compared to the other data correlation teams) if you do simple dumb stuff. I'm certain they take into account those trying to be privacy-conscious, if only to increase their match rates to be competitive.