Mark Zuckerberg survived 5 hours of relentless questioning from Congress - here's what you need to know

Andrew Harnik/AP

• Facebook CEO Mark Zuckerberg testified before the US Senate in a gruelling five-hour session on Tuesday.
• Zuckerberg's delivery was wooden, and stuck closely to company talking points - but didn't make any major mistakes.
• Many of the senators were painfully tech illiterate, and the 33-year-old exec found himself explaining basic features of Facebook.
• His answers to some of the tougher questions were less satisfying, but he was never pushed as hard as he could have been.

Mark Zuckerberg didn't really screw up. This time, at least.

On Tuesday, the Facebook CEO testified in front of a rare US Senate joint committee hearing. The subject: Facebook's mounting scandals, from the misappropriation of up to 87 million users' profile data by Cambridge Analytica to Russia's use the platform to spread propaganda and misinformation.

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The stakes were high, and a major misstep had the potential to be played ad nauseam across cable news, and define Zuckerberg's - and Facebook's - public image for years. (Recall when, in a notorious 2010 on-stage interview, the executive grew so flustered and sweaty he had to take his hoodie off.)

The 33-year-old CEO is not a natural speaker, and he stuck closely to talking points with a somewhat robotic delivery. Facebook's new, broader view of its responsibilities was constantly referenced, while his frequent references to starting Facebook in his dorm room even drew jokes from some senators.

But he managed to basically stay on message throughout the five-hour hearing. Facebook is very sorry, it made a "big mistake," it's proactively making significant changes to prevent this happening again, and so on. His remarks closely echoed what he and other executives have repeated in numerous blog posts and press interviews over the last week or so - and shows how Facebook has managed to largely stay ahead of lawmakers' questions.

Attempts by high-profile Republican senators like Ted Cruz to highlight perceived left-wing bias at the company failed to elicit a damaging reaction from Zuckerberg. And the tech illiteracy of many senators was on painful display, with Zuckerberg repeatedly having to explain basic concepts and features of Facebook: Zuckerberg explained Facebook doesn't sell user data at least three times.

When it came to harder questions from more tech-literate senators - who asked questions about trust, potential violations of an FTC order, and conversations inside the company - Zuckerberg's answers were less satisfying. But with only five minutes per senator, he was never pushed as far as he could have been.

The embattled executive isn't out of the hotseat just yet. On Wednesday, he will appear again before Congress, this time in front of a House committee. That hearing that could easily run as long as Tuesday's affair, if not even longer.

Here's the key news from Tuesday's Senate hearing:

• Facebook employees have been interviewed by the special counsel's office. Mark Zuckerberg revealed that unspecified employees from his company have been interviewed as part of Robert Mueller's investigation into Russian interference in the 2016 US presidential election. (Zuckerberg himself has not been interviewed.)
• Facebook was accused of violating a 2011 FTC order, which Zuckerberg denied. The order stipulated how Facebook must protect user data and obtain consent before it is shared, and senators suggested that the Cambridge Analytica scandal means Facebook failed in that. Zuckerberg's (unsatisfying) defence: Users supposedly technically consented to it, even if the systems Facebook had built were clearly flawed. "We explained to people how it worked and they did consent to it," he said.
• Facebook has considered offering an ad-free, subscription option for users. "In general we believe the ad model is the right one for us," Zuckerberg said. "Certainly we consider ideas like that ... [it is] reasonable to think through." However, he says that there will always be a "version" of Facebook that's free.
• Zuckerberg admitted most users don't read the social network's terms of service before signing up. The mammoth legalese documents new users are supposed to agree to came up multiple times throughout the hearing. "I would imagine that probably most people do not read the whole thing, but everyone has the opportunity to, and consents to it, he said.
• Facebook does not have "specific knowledge" of Russia or China scraping data and building profiles on users. Zuckerberg said Facebook is still investigating the Cambridge Analytica scandal and who else had harvested user data, but "I don't think sitting here today we have specific knowledge of other efforts by these nation states."
• Zuckerberg got grilled over Facebook's perceived political bias. Republican senator Ted Cruz outlined what he alleged was a "pervasive pattern of bias and political censorship" - from the closure of right-wing pages to the alleged suppression of conservative news stories - and hit the CEO with multiple leading questions. But the CEO handled the exchange reasonably well, holding his own.
• Zuckerberg refused to say what hotel he was staying in. In an awkward exchange, top Democratic senator Dick Durbin asked the CEO what hotel he was staying in, which he refused to answer."I think that might be what this is all about," Durbin told Zuckerberg. "Your right to privacy, the limits of your right to privacy, and how much you'd give away in modern America."

For more on the Senate hearing, check out Business Insider's complete liveblog of the event »