Facebook boss Mark Zuckerberg has apologised for failing to protect user data in the wake of the Cambridge Analytica scandal.

In an eagerly-anticipated appearance before US Congress onTuesday, Zuckerberg said, "We didn't take a broad enough view of our responsibility and that was a big mistake."

"It was my mistake, and I'm sorry. I started Facebook, I run it, and I'm responsible for what happens here."

On the subject of fake news, Zuckerberg said "one of my greatest regrets in running the company" was its slowness at uncovering and acting against disinformation campaigns by Russian trolls during the US election.

He agreed to testify after revelations that Cambridge Analytica, a data-mining firm with links to Donald Trump's presidential campaign, gathered personal information from 87 million users to try to influence elections.

Facebook says more than 70 million of the affected users are in the US, though there are over a million each in the Philippines, Indonesia and the UK.

More to follow...