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Mark Zuckerberg testimony as it happened: Facebook CEO grilled by senators

Mark Zuckerberg is under pressure to explain how Facebook allowed the personal information of millions of its users to be scraped by a political ad firm.

Thanks for tuning into the Mark Zuckerberg Congressional Testimony Live Blog Extravaganza from NBC News!

Facebook CEO Mark Zuckerberg testified before Congress Tuesday and it lasted nearly five hours. He'll be back Wednesday for another round of questioning.

Catch up on what went down in our blog below.

Live Blog

Final Status Update

Four hours and 54 minutes after he began testifying, Zuckerberg is done. He was contrite, and he neither agreed to nor objected to most of the senators’ suggestions, pet bills and light condemnations. As many senators noted, regulation could actually be a good thing for Facebook — as could a lack of new regulation. But all in all, Zuckerberg emerged unscathed.

Zuckerberg notes photographed with bulleted talking points

Zuckerberg's notes during the hearing included talking points around how to defend Facebook, election integrity, and, of course, Cambridge Analytica.

Did Facebook have the right incentives?

Sen. Maggie Hassan, D-N.H., told Zuckerberg she wants to look into creating financial penalties for companies that don’t protect consumers’ private information.

“There is little incentive, whether it’s Facebook or Equifax, to actually be aggressive in protecting customer privacy,” said Hassan. “We’ve heard apologies but there is no financial incentive.” Zuckerberg said he’d look forward to a discussion of financial penalties, but he took issue with the idea that Facebook hasn’t felt pain.

“This episode has clearly hurt us,” he said.

While the company’s stock soared 4.5 percent Tuesday as Zuckerberg testified, its closing price of $165.04 per share was down from $193.09 on February 1.

'Your user agreement sucks' and other gems from Sen. Kennedy

In his relatively short time in the Senate, John Kennedy, R-La., has developed a reputation for delivering the best one-liners in the chamber. Though he had to wait four hours to question Zuckerberg Tuesday, he was ready with his quote machine. Here are the top 5 quotes from Kennedy.

1. "Your user agreement sucks."

2. "The purpose of that user agreement is to cover Facebook's rear end."

3. "I don’t want to regulate Facebook, but my God, I will."

4. "There are some impurities in the Facebook punch bowl."

5. And, he told the social network titan, "I feel like we’re not connecting."

Sen. Harris drills down on why Facebook didn't tell users about Cambridge Analytica

Sen. Kamala Harris, D-CA, asks a very pointed question and doesn't let Zuckerberg dodge — did Facebook discuss notifying its users that their data had been taken by a researcher that worked Cambridge Analytica when the company found out about the data's misuse?

"Senator, in retrospect, we clearly view it as a mistake that we didn't inform people and we did that based on false information that the case was closed and the data had been deleted," Zuckerberg said.

Sen. Harris quickly interjected, "so, there was a decision made on that basis not to inform the users, is that correct?"

"That's my understanding, yes. And knowing what we know now, there's a lot of things we should have done differently," Zuckerberg said.

We're in our last break of the day

We're in the final stretch for the evening! After the short break, there will be 13 remaining senators. 

Finally, someone asks if Facebook is spying on us through smartphone microphones

Everything today has been a precursor to this.

Sen. Gary Peters, D-MI, asks whether Facebook is listening to people's conversations through microphones in their smartphones. This is an amazing question because there is a group of people who fervently believe that Facebook is always listening to us and then using that information to target ads.

This has been a running conspiracy theory that Mark Zuckerberg has now responded to.

Zuckerberg says that the company does not.

And really, isn't it more impressive that Facebook can target ads so well that people think all their conversations are being listened to?

Facebook does delete your data

Zuckerberg told Sen. Heller, R-N.V., that Facebook does delete a user's data if they fully cancel their account. But he didn't know off the top of his head how long Facebook hangs out to a user's data before deleting it.

Facebook says it can take up to 90 days for the company to delete a user's data after they delete their account: "It may take up to 90 days from the beginning of the deletion process to delete all of the things you've posted, like your photos, status updates or other data stored in backup systems. While we are deleting this information, it is inaccessible to other people using Facebook."

No perfect solution on election protection

Democratic senators have asked Zuckerberg time and again what he plans to do to make sure Facebook doesn’t get used to improperly influence elections, and he says that’s a top priority heading into the 2018 midterms in November.

He wants to make it “much harder in the future” for outside actors to impropoerly interfere in elections.But, he said, he can’t promises that images spread in 2016 won’t appear on Facebook again.

“I can’t guarantee that,” he said. “I don’t think it would be a realistic expectation … that we’re going to have zero amount of that and that we’re going to be 100 percent successful” at preventing it.

Why Zuckerberg has had a bit of an edge at times

MSNBC's Kasie Hunt notes that it became pretty evident in the first half of the hearing that some of the questions asked by senators in their 60s and 70s don't quite understand the basics of Facebook technology, which has left Zuckerberg in a prime spot to fire back or divert.

What about the News Feed algorithm?

The senators have covered a decent amount of ground so far today, but one thing that hasn't been asked — what's up with the algorithm that runs Facebook's News Feed?

The News Feed is the most central and important part of Facebook, and it's how the social network controls what people see. The company can — and does — tweak it, most recently announcing that people would be seeing less news and more from their friends.