Actually, you absolutely can on https://www.facebook.com/ads/preferences/

- Advertisers you've interacted with

- - Who have added their contact list to Facebook

Hover over those you don’t know about; the X let you “Remove” those, i.e. ask Facebook to exclude you from those advertisers’ targeting.

If you are in Europe, you should be able, starting next month, to leverage that list to ask those advertisers how they got your data, and expose data brokers. Facebook is simply (finally) offering you the ability to track data brokers.