In two days of televised hearings, Facebook leader Mark Zuckerberg tried last week to assure Senate and House members that the social media giant gets it. In his first congressional appearance, the 33-year-old apologized repeatedly for not fully protecting personal information, for not spotting serious mischief more quickly and for not making it simpler for 2 billion users to understand service terms and privacy settings. "It's clear now that we didn't do enough to prevent these [Facebook] tools from being used for harm," said the chief executive of the company he founded in 2004. "That goes for fake news, foreign interference in elections and hate speech, as well as developers and data privacy. 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."

Extraordinary circumstances led up to the 10 hours of testimony: The 2016 presidential election showed Facebook's power to let political propaganda spread through its inaction. Also, its carelessness with data-grabbing tools exposed 87 million users to a shady researcher who sold his findings to the data firm Cambridge Analytica, and maybe others. As Zuckerberg sat in front of them, almost 100 Capitol Hill lawmakers asked nearly 600 questions – many harsh, some grandstanding and others confused about how Facebook works. He was asked whether the company should be more heavily regulated, whether it intentionally censors conservative content and how much Russians may be meddling with America's democratic process through the site.

Federal lawmakers are considering how to regulate internet power players. European officials already impose limits on Facebook, requiring it to stop using facial recognition technology within the European Union and curbing some of its internet-use tracking practices. Senators and representatives indicated last week that similar steps may be ahead here. “The hearings sent an obvious message, writes Matthew Ingram, chief digital reporter for Columbia Journalism Review. "Congress thinks Facebook is up to something – even if it's not too sure what it is exactly – and they’re willing to consider legislation to clean things up." Here's how Sen. John Kennedy, R-La., put it to the star witness: "I don't want to vote to have to regulate Facebook, but by God I will."

Zuckerberg says: "It will take some time to work through all of the changes we need to make, but I’m committed to getting it right." – Senate hearing opening statement

Senator tells Zuckerberg: "Here's what everyone's been trying to tell you, and I say this gently: You user agreement sucks." – Sen. John Kennedy, R-La.

Congressman says: "You're truncating the basic rights of the American promise of life, liberty, and the pursuit of happiness by the wholesale invasion and manipulation of their right to privacy." – Rep. Bobby Rush, D-Ill., to Zuckerberg.