Mark Zuckerberg doesn't give a lot of TV interviews. This week he sat down for one with CNN's Laurie Segall.
The press-shy Facebook CEO spoke with Segall as part of an effort to publicly address a scandal over privacy that has rocked the company. News broke over the weekend that Cambridge Analytica tried to influence American voters using data taken from Facebook profiles that had been accessed improperly.
Here are some of the most interesting things he said.
1. "This was a major breach of trust, and I'm really sorry that this happened."
For the first time since the Cambridge Analytica story broke, Zuckerberg said he was sorry. Earlier in the day, he published a blog post taking responsibility for the misuse of the data of tens of millions of Facebook users. He outlined a plan to make sure user data is protected.
2. "We're going to review thousands of apps."
Facebook changed its platform in 2014 to limit developer access to user information. But users downloaded plenty of third-party apps before then. Now, Facebook is reviewing apps that may have misused data before 2014, and plans on letting affected users know.
3."We should not have trusted the certification that [Cambridge Analytica] gave us. And we're not gonna make that mistake again."
Facebook says that Cambridge Analyica assured it in 2015 that the information in question was destroyed. But self-described whistleblower Christopher Wylie, a former Cambridge Analytica contractor, told news outlets that the data is still out there.
4. "If we go in and find that Cambridge Analytica still has access to the data, we're gonna take all legal steps that we can to make that the data of people in our community is protected."
Facebook asked Cambridge Analytica to agree to an audit to show that the data was deleted, as the data firm promised in 2015.
5. "We've started off a little bit on the idealistic, and maybe naive, side ... what we've learned over time very clearly is that the most important thing always is making sure that people's data is locked down."
The Cambridge Analytica scandal has put Facebook under scrutiny for its privacy practices — again.
6. "One of the big misconceptions about Facebook is this idea that we somehow sell data ... we don't want data to be able to get out. When that happens, that's not good for people in our community, that's not good for our business."
Zuckerberg bristled at the suggestion that Facebook sells data. He explained that it is in his company's best interest to hold on to user data, because it gives Facebook a competitive advantage. In other words, Facebook doesn't sell user data because it wants it for itself.
7. "This isn't rocket science ... there's a lot of hard work that we need to do to make it harder for nation-states like Russia to do election interference, to make it so that trolls and other folks can't spread fake news, but we can get in front of this."
Soon after the 2016 US presidential election, Facebook announced a series of measures to prevent fake news from spreading on the social platform. The company has promised to double the amount of people working on safety and security from 10,000 in 2017 to 20,000 by the end of this year.
8. "I'm sure that there's V2 — version two of whatever the Russian effort was in 2016 — I'm sure they're working on that."
Zuckerberg believes that bad actors are trying to use Facebook to interfere with elections. In particular, the company has seen attempts to sow discord on the platform. Zuckerberg thinks Facebook knows enough now to get ahead of their efforts.
9. "Security isn't a problem that you ever fully solve. You can get to the level where you're better than your adversaries and they continue evolving, so we're going to be working on this forever."
Even with a 20,000-person security team, there are no guarantees.
10. "I'm happy to [testify in Congress] if it's the right thing to do."
Several lawmakers have called on Zuckerberg to testify before Congress, and he opened the door to that possibility on Wednesday. But, he added, he'll only testify if he's the best person for the job.
11. "I actually am not sure we shouldn't be regulated ... the question is more, what is the right regulation rather than 'Yes or no, should it be regulated?'"
Lawmakers are already considering a regulation that would affect political advertising on Facebook. The Honest Ads Act would require the same disclosures for online political ads that currently apply to television and radio spots. Supporters say that would add protections against foreign interference.
Facebook did not confirm whether this was the legislation Zuckerberg had in mind when he spoke to Segall.
12. "I've made every kind of mistake that you can make. I mean I started this when I was so young and inexperienced, right? I made technical errors and business errors. I hired the wrong people. I trusted the wrong people. I've probably launched more products that have failed than most people will in their lifetime."
Regrets, he has a few.
13. "I used to think that the most important thing to me by far was ... having the greatest positive impact across the world that I can, and now I really just care about building something that my girls are gonna grow up and be proud of me for."
A rare emotional moment from the Facebook CEO.
— Charles Riley and Donie O'Sullivan contributed to this report.