Anonymization is a myth. If you sell ads on proxy data, that data can be deanonymized. Also, Facebook may not directly sell your social security but they sure will buy it from the less scrupulous (but more honest) companies.
The ad space is data. If you chose the right categories you can reasonably identify someone. The whole purpose of behavioral advertising is to identify groups, you can make those groups =1 if your clever. Look up deanonymization. It's one of those problems that also affect researchers because it's hard to keep db data anonymous too.
You need to read up on how online advertising works. Or better yet spend a couple of dollars and try it yourself. None of what you are saying makes any sense.