https://www.msn.com/en-us/news/politics/...ions/ar-BBKkWOF

So the firm harvested private information from the Facebook profiles of more than 50 million users without their permission, according to former Cambridge employees, associates and documents, making it one of the largest data leaks in the social network's history. The breach allowed the company to exploit the private social media activity of a huge swath of the American electorate, developing techniques that underpinned its work on President Trump's campaign in 2016.