https://qz.com/1267180/facebook-ceo-mark-zuckerberg-is-threatened-with-a-formal-summons-by-the-uk-parliament/

UK lawmakers are well and truly fed up with Facebook CEO Mark Zuckerberg, and have ordered him to appear for parliamentary questioning or face a formal summons the next time he sets foot on British territory.

Last week, Facebook chief technical officer Mike Schroepfer participated in UK hearings about the Cambridge Analytica scandal. Schroepfer was mercilessly grilled by members of Parliament (who were notably more well-informed than their peers in the US Congress).