https://www.theguardian.com/news/2018/mar/20/facebook-data-cambridge-analytica-sandy-parakilas

Sandy Parakilas says numerous companies deployed these techniques – likely affecting hundreds of millions of users – and that Facebook looked the other way

Hundreds of millions of Facebook users are likely to have had their private information harvested by companies that exploited the same terms as the firm that collected data and passed it on to Cambridge Analytica, according to a new whistleblower.