Updated at 7:35 p.m. ET
Mark Zuckerberg faced dozens of senators — and the American television audience — to take "hard questions" on how Facebook has handled user data and faced efforts to subvert democracy.
"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," the co-founder and CEO of Facebook, uncharacteristically wearing a suit, said in his opening remarks. "I started Facebook, I run it, and I'm responsible for what happens here."