Cambridge Analytica harvested 50 million Facebook users' data for Trump campaign

According to whistleblower Christopher Wylie, during the 2014 US midtern elections, Cambridge Analytica, needing data to complete the new products it had promised to political advisor Steve Bannon, harvested private information from the Facebook profiles of more than 50 million users without their permission. There was enough information about 30 million of these users to match them to other records and build psychographic profiles. 

After the news became public in March 2018, Facebook suspended the accounts of Cambridge Analytica, Wylie, and researcher Aleksandr Kogan. Britain's information commissioner has announced she is to investigate whether the data was illegally acquired and used, and both the UK Parliament and the US Congress have called Facebook CEO Mark Zuckerberg to testify. 

https://mobile.nytimes.com/2018/03/17/us/politics/cambridge-analytica-trump-campaign.html
http://www.bbc.co.uk/news/technology-43581892
Writer: Matthew Rosenberg, Nicholas Confessore and Carole Cadwalladr
Publication: New York Times, BBC