5 ms·
> The "opt-out" is just another cookie. There's nothing special about them either, they can be used to track return visitors just as well as any other cookie. I
by fhrow4484 6y ago
> The "opt-out" is just another cookie. There's nothing special about them either, they can be used to track return visitors just as well as any other cookie. I'm sure they're not, because that would be against the spirit of the law ..
How is a opt out cookie the same as tracking cookie?
Isn't there a clear difference for a cookie:
is_opt_out: true
Compared to a cookie:
tracking_id: 374739585483292
Sure the first one can tell server "this is a user that had visited the page in the past". But this is nothing compared to the second one which tells server "this is this specific user"
- est31 6y agoYou might think it's just one bit of fingerprinting information, but if 99 of 100 users click "accept" and one user clicks "decline", it's suddenly become 6.6 bits. Now combine that with other fingerprinting data and you have uniquely identified the user. It's the same problem with pages where most users are logged in: the few who aren't are suddenly such a small group that they become identifiable through other means.
- jcheng 6y agoCan you explain how you got 6.6 bits?
- aDfbrtVt 6y agoBecause it uniquely describes a user within a group of 100 other people. 2^(-6.6) ~ 1/100
- user2342234 6y agoFrom Shannon's formula for information content[1]. The Idea is that the less likely an event is the more information it imparts. I = -log2(p) In this case they used p = 1/100 1 - https://en.wikipedia.org/wiki/Information_content https://en.wikipedia.org/wiki/Information_content
- marksomnian 6y agolog2(1/100)