Facebook learned about Cambridge Analytica as early as September 2015, new documents show - Shocking documents reveal how Facebook employees knew voters were targeted in 2016

https://www.reddit.com/r/worldnews/comments/cud6ei/facebook_learned_about_cambridge_analytica_as/

https://www.cnbc.com/2019/08/23/facebook-releases-new-cambridge-analytica-documents.html