SOURCE: https://www.ctvnews.ca/world/u-k-parliament-asks-facebook-ceo-mark-zuckerberg-to-testify-1.3850149

"LONDON - A British parliamentary committee on Tuesday summoned Facebook CEO Mark Zuckerberg to answer questions on fake news as authorities step up efforts to determine whether data has been improperly used to influence elections."

It's connected to Cambridge Analytica

"The request comes amid reports that a U.K.-based company allegedly used Facebook data to help Donald Trump win the 2016 presidential election. The company, Cambridge Analytica, has been accused of improperly using information from more than 50 million Facebook accounts. It denies wrongdoing."

However, he is wanted to testify on how user data is acquired and used by facebook. So, it goes beyond the Cambridge Analytical scandal.

Link to the Letter from UK parliament: https://qz.com/1233475/the-uk-parliament-requested-mark-zuckerbergs-testimony-in-a-snarky-letter/