Cambridge Analytica whistleblower: 'We spent $1m harvesting millions of Facebook profiles' – video
Christopher Wylie, who worked for data firm Cambridge Analytica, reveals how personal information was taken without authorisation in early 2014 to build a system that could profile individual US voters in order to target them with personalised political advertisements. At the time the company was owned by the hedge fund billionaire Robert Mercer, and headed at the time by Donald Trump’s key adviser, Steve Bannon. Its CEO is Alexander Nix
