Your question is an oversimplification of the issue. A St. Petersburg University professor received permission( four years age) from Facebook to assemble a list of 50 million users for a research project. The list of users was used by Cambridge Analytica with a personality test app to query Facebook users. Consenting users gave the researcher permission to access their Facebook information(approx. 100,000+ gave consent).
The user group that permitted their Facebook information to be collected by a third party are not a reliable sample for decision making.