https://www.cnbc.com/2018/03/19/facebook-shares-fall-over-fallout-from-cambridge-analytica-scandal.html

Facebook shares fell over 3 percent in pre-market trade Monday after reports that Cambridge Analytica mined the data of over 50 million users of the social network without their permission.

Cambridge Analytica worked on Facebook ads for President Donald Trump during the 2016 election. It was initially funded by conservative billionaire Robert Mercer and led by former Trump advisor Steve Bannon.