"We didn't take a broad enough view of our responsibility, and that was a big mistake". I took to the rainy streets of Seattle's Fremont neighborhood to find out.
"I think it's an important principle", said the Facebook chief, and that it "deserves a lot of discussion".
Lawmakers have sought assurances that Facebook can effectively police itself, and few came away from Tuesday's hearing expressing confidence in the social network.
CA has been accused of mining personal information of millions of Facebook users illegitimately to help political campaigns and influence polls in several countries. Here's what we did learn.
Lauren Davis, an employee at Virginia Mason, isn't sure how she feels about Facebook's user data scandals.
"Consumers ought to have clearer information, not opaque policies and complex click-through consent pages", said Republican Sen.
On the subject of fake news, Mr Zuckerberg said "one of my greatest regrets in running the company" was its slowness at uncovering and acting against disinformation campaigns by Russian trolls during the USA election.
"Was your data included in the data sold to the malicious third parties?"
Although numerous questions that were asked seemed a bit off-topic-often due to the apparent lack of understanding about the company-some senators did focus their attention on the topic at hand.
That is: proposed legislation that could limit Facebook and its ilk more than any before it.
For months, Diamond and Silk have said Facebook was preventing their videos from reaching fans.
The flub raised larger questions around how Facebook goes about vetting content and whether or not it's biased. Zuckerberg confirmed that it could not, explaining that Whatsapp is an encrypted app, which Facebook doesn't have access to.
Zuckerberg says he doesn't think Facebook has a monopoly. Later that year, Facebook began auto-sharing what people were reading with their friends. "That's the only way we can reach billions of people".
Facebook introduced the "Like" button for web pages in 2010. There have been reports that Facebook can track a user's internet browsing activity even after that user has logged off of the Facebook platform.
The 33-year-old founder, chair, and CEO of Facebook returned to Congress on Wednesday to answer a variety of questions about his social media platform before the House Energy and Commerce Committee.
You may have heard that Facebook is under fire after recent allegations of unauthorized access and use of people's Facebook profiles, according to a recent statement from the federal privacy commissioner.
Zuckerberg acknowledges that the Facebook user agreement is problematic..
Yes, users voluntarily post data to their timelines. Zuckerberg countered that putting together a concise agreement has been a challenge.
"For as long as Russian Federation has people employed who are trying to perpetrate this kind of interference, it will be a hard for us to guarantee that we're going to fully stop everything", he said. "Your user agreement sucks".