[C4stor]

Remove userid / cookie sync / whatever you name it from bid requests, and make them only context based. Also, forbid cookies from ads providers to be stored on the end user machine.

Note that this doesn't disallow websites with first party data and user consent to add user related information to the bid requests to increase their value, it just doesn't allow to correlate the information with a person after the RTB process ends. Of course it totally changes the role of data providers in the current ecosystem, but that wouldn't necessarily be a bad thing.