That’s not how it works. Users are grouped into large audiences, anonymized, and sold. For example, your credit card purchase data is sold by visa but visa will

That’s not how it works. Users are grouped into large audiences, anonymized, and sold. For example, your credit card purchase data is sold by visa but visa will not create and sell an audience that has less than 1mm users in it (and then gets modded with look a likes to 5-150mm users). There are some random articles about deanonymizing location data, but very much a powerful dark government level thing, and those groups have better ways of doing it.