https://finance.yahoo.com/news/facebook-releases-privacy-safeguards-ceding-151134311.html

Facebook has also set up new procedures for the handling of names of potential customers supplied by data brokers. Advertisers seeking to upload lists of these prospects onto Facebook's platform will first have to promise that the data vendor obtained any legally required consent from those consumers.

Facebook says the new policies will create more transparency for its users and require more accountability from advertisers.