Since 2012, Facebook has been working with data brokers to acquire even more information on its users. According to a report from ProPublica, this information can include a user’s income, restaurant habits, and credit card activities.

Combine third party data with what Facebook already knows about its users from using the social network and it is hard to think of any piece of information the company doesn’t have about a person.

While there are theoretically ways to op-out of letting Facebook use third party information, most users don’t know about them and Facebook told ProPublica the company feels no particular obligation to tell users because it is merely buying information available to anyone:

“Our approach to controls for third-party categories is somewhat different than our approach for Facebook-specific categories,” said Steve Satterfield, a Facebook manager of privacy and public policy. “This is because the data providers we work with generally make their categories available across many different ad platforms, not just on Facebook.”

But can you actually opt-out of the third-party categories/data broker system itself? Not really.

You can ask to be removed from a data broker company’s database, which often requires submitting a written request to the company with a copy of a driver’s license or some other official identification. But a detailed case study revealed even that did not work with a majority of data brokers.

The data broker industry is somewhat regulated by the Federal Trade Commission (FTC), which occasionally brings actions against companies if they get caught doing particularly egregious things. But for the most part, data brokers are free to do as they will because few laws exist to rein them in.

In 2014, the FTC made a detailed proposal for Congress to write laws to regulate the new industry. The FTC claimed data brokers “operate with a fundamental lack of transparency.”

People regularly ask how Facebook, with its massive data management costs, can offer its service for free. The answer is simple, the product is you.