Zuckerberg agreed to meet leaders of the European Parliament to answer questions about how political consultancy Cambridge Analytica improperly got hold of the personal data of 87 million Facebook users, including up to 2.7 million in the EU.

In his opening remarks, Zuckerberg said it had "become clear over the last couple of years that we haven't done enough to prevent the tools we've built from being used for harm as well."

"Whether it's fake news, foreign interference in elections or developers misusing people’s information, we didn’t take a broad enough view of our responsibilities.

That was a mistake, and I’m sorry."