Among the lawmakers' concerns: How Facebook might make up possible abuses to its users — and whether Zuckerberg himself is telling the truth when he promises to obey Europe's privacy laws.
Facebook CEO Mark Zuckerberg took questions from members of the European Union Parliament on Tuesday about allegations that personal data of European Facebook users was misused. The testy session ended with several members of Parliament complaining that Zuckerberg had failed to address their most pressing questions.
Zuckerberg conceded that Facebook had not been ready fight off fake news that spread quickly on its site. And he apologized for the improper use of millions of users' data to help political campaigns, after an analytics company gained information that had been collected by a quiz app.
"Whether it's fake news, foreign interference in elections or developers misusing people's information, we didn't take a broad enough view of our responsibilities," Zuckerberg said. "That was a mistake, and I'm sorry."
As was the case when Zuckerberg testified on Capitol Hill last month, some exchanges included awkward moments. But today, many of those instances were due to close and even personal questioning of the Facebook founder — not from U.S. lawmakers asking how Facebook makes money without charging users, or its stance on Chick-Fil-A Appreciation Day.
In Brussels, much of the discussion centered on the potential impact of social media and privacy worries on Europe's elections that are slated for next year. But when pressed about Facebook's business practices and its use of data, Zuckerberg left the EU leaders wanting more.
Zuckerberg visited the EU a month after Facebook introduced "new privacy experiences" to comply with European regulations that are meant to give users more control over their personal data and prevent abuse.
Each of the members of the European Parliament in today's session got 3 minutes to ask a question; Zuckerberg was to reply to them all at the end. But the format chafed the politicians, and when the session ended after running 15 minutes over its allotted time, Zuckerberg was left promising to use other means to answer their questions.
One unanswered question centered on whether Facebook cross-references data from its users and users of WhatsApp. But many others were also passed by, including anti-trust questions and queries about how the company treats its users.
"Will you allow users to escape targeting advertising?" Belgian Philippe Lamberts said as the meeting was nearly over.
A leader of the Greens party, Lamberts added, "I mean, I asked you six yes or no questions — I got not a single answer. And of course, well, you asked for this format for a reason."
"I'll make sure we follow up and get you answers for those," Zuckerberg said.
Britain's Syed Kamall of the European Conservative Group asked Zuckerberg, "How can non-users stop Facebook collecting their data?" He also asked how Facebook commercializes that data.
Guy Verhofstadt, the Belgian leader of the centrist Alliance of Liberals and Democrats for Europe, opened his remarks by comparing Zuckerberg to the CEO of an "out of control" big data company in novelist Dave Eggers' book The Circle.
"It seems to me, very near to reality," Verhofstadt said, noting that the fictional company's data was also used to affect elections.
He added, "also the fact that maybe you have less control, or no control, about your own company for the moment, because you have to apologize now – I think in total you apologized now 15 or 16 times" in the last decade.
"Are you capable to fix it?" Verhofstadt asked Zuckerberg. before mentioning the way public regulations cover banks – which often say they will fix their own problems. He then moved on to equally pointed questions.
"Are you telling the truth, in fact, to us?" he asked the Facebook CEO about the company's pledge to adhere to Europe's privacy laws.
"Since the outbreak of Cambridge Analytica, you have massively transferred European data of non-European citizens out from Europe, away from European servers," Verhofstadt said.
"I have to tell you, that's against the regulations," Verhofstadt said, wagging his finger. He added that the company had taken the same step with data it has collected about Europeans who are not Facebook users.
He then asked, "Will you compensate the European Facebook users?"
One approach, Verhofstadt said, would be to base a payment on the value each person brings to the company through their social media account.
"My value as a Facebook user is $186," Verhofstadt said. "I thought it was more, but... maybe my wife thinks it's less."
Verhofstadt asked Zuckerberg whether Facebook will open its books to show whether the company is a monopoly – and how it might resolve that question."
"I really think we have a big problem here," Verhofstadt said.
"You have to ask yourself how you will be remembered," he said, looking at Zuckerberg: "As one of the three big Internet giants, together with Steve Jobs ... and Bill Gates, who have enriched our world and our societies – or at the other hand, in fact, [as] a genius who created a digital monster, that is destroying our democracies and our societies."
An apology from Facebook "is absolutely needed," Germany's Manfred Weber said. He then asked whether Cambridge Analytica is an isolated case. And he asked why Zuckerberg did not tell users sooner that Facebook data had been misused.
Zuckerberg began his responses by discussing Facebook's work in what he called "sensitive areas" where there is a chance of the most serious harm: terror; bullying; self-harm, election integrity.
He described an arms race in which Facebook uses Artificial Intelligence to try to police its systems – and malignant actors use some of the same AI tools to try to skirt the rules, often for financial gain.
Zuckerberg said that in the first quarter of 2018, Facebook took down "about 580 million fake accounts – the vast majority within minutes of being registered."
For any questions that were not answered, Zuckerberg agreed to submit written replies over the next few days.
"We are the regulators," Parilament President Antonio Tajani said at the start of the session, describing a new system of operating in the digital market.
In his opening remarks, Zuckerberg said "it's also become clear" that Facebook hadn't done enough to prevent abuse by companies and other entities that use apps to access users' information.
"I'm committed to getting this right," he also said.
Discussing "important elections globally" over the next 18 months, Zuckerberg said, "We weren't prepared enough" for the type of social media attacks and manipulation that have now emerged.
This year, Facebook is doubling the number of people working on security, to more than 20,000 employees by the end of 2018, Zuckerberg said.
In addition to concerns about hundreds of millions of EU voters being able to act without worrying about false and warped information and opinions, Tajani said social media companies must also work to prevent being used as tools by terrorists.
The Facebook founder outlined how the company had evolved from the days in which it relied on its community members to flag content, to be reviewed later.
Zuckerberg said, "If you look for example at terror content, one of the things that I'm proud of is that our AI systems now can flag 99 percent of the ISIS and al-Qaeda -related content that we end up taking down before any person in our community flags that for us."