Facebook: We were hacked

Personal data on users and their Facebook friends was easily and widely available to developers of apps before 2015.

Facebook in March declined to say how much user data went to Cambridge Analytica, saying only that 270,000 people had responded to a survey on an app created by a researcher in 2014. The researcher was able to gather information on the friends of the respondents without their permission, vastly expanding the scope of his data. That researcher then passed the information on to Cambridge Analytica.

Facebook declined to say at the time how many other users may have had their data collected in the process.

A Cambridge Analytica whistleblower, former researcher Christopher Wylie, said last month that the real number of people affected was at least 50 million. Wylie tweeted yesterday that Cambridge Analytica could have obtained even more than 87 million profiles.

Cambridge Analytica responded to Facebook’s announcement yesterday by saying that it had licensed data on 30 million users.

It has denied any wrongdoing in collecting or using Facebook data.

Cambridge Analytica was founded by a multimillion-dollar investment by hedge-fund billionaire Robert Mercer and headed by his daughter, Rebekah Mercer, who was the company’s president, according to documents provided by Wylie. Serving as vice-president was conservative strategist Stephen Bannon, who also was the head of Breitbart News. He has since left both jobs and also his post as a top White House adviser to Trump.