REUTERS

"We've invited Mark Zuckerberg to the European Parliament. Facebook needs to clarify before the representatives of 500 million Europeans that personal data is not being used to manipulate democracy," EP President Antonio Tajani wrote on Twitter.

Read alsoCambridge Analytica expose: key revelations of investigative journalistsAs UNIAN reported earlier, Cambridge Analytica whistleblower revealed how firm linked to former Trump adviser Steve Bannon compiled user data to target American voters.

The data analytics firm that worked with Donald Trump's election team and the winning Brexit campaign harvested millions of Facebook profiles of U.S. voters, in the tech giant's biggest ever data breach, and used them to build a powerful software program to predict and influence choices at the ballot box.