Facebook's Chief Executive Mark Zuckerberg spent two days this week facing scrutiny from U.S. lawmakers, but the social network he helped create isn't in the clear just yet.
The firm's billionaire co-founder told lawmakers at the two-day Congress hearing of how his own data had been compromised as a result of the data scandal haunting the company. He said the company failed to notify the Federal Trade Commission about the leak of users' data to controversial political data analytics firm Cambridge Analytica.
Now Facebook faces further scrutiny in Europe.
Chief Technology Officer Mike Schroepfner is due to appear before U.K. lawmakers later this month to address the ongoing data scandal enshrouding the company. Stepping in for the firm's CEO, Schroepfner will face questions from the U.K. Digital, Media, Culture and Sport select committee, chaired by Damian Collins, on April 26.
British lawmakers still want to hear from the Facebook boss, however. After Zuckerberg declined an invitation to appear before British lawmakers, Collins, a parliamentarian from Britain's governing Conservative Party, sent Facebook a letter insisting that Zuckerberg give evidence before the committee.
Facebook has admitted that the data of 87 million users' profiles — even Zuckerberg's — may have been shared without their permission to controversial political data analytics firm Cambridge Analytica. The social network has been letting users know whether their data was compromised since Monday.
"People will seek to clarify the converging testimonies, especially on the more technical aspects where he (Zuckerberg) was obscuring and giving evasive answers," Paul-Olivier Dehaye, co-founder of PersonalData.IO, told CNBC in a phone interview.
Some commentators have said that U.S. politicians did not ask difficult enough questions to the Facebook CEO. That is something that could change when Schroepfner gives evidence, Dehaye said.
On Thursday, the European Union's data watchdog said it would scrutinize social media firms further with a Social Media Working Group. The EU is preparing to enforce a new data law that could lead to fines of up to 4 percent of a company's annual global turnover if breached.
Dehaye, who has himself appeared before U.K. lawmakers, said that Europe was likely to be much tougher on Facebook and big tech companies than the U.S.
"The evasiveness that Zuckerberg has displayed will be much harder to display on the European side," he said, adding, "The questions by elected representatives will be much more pointed on points of facts. I think that's the main shift that will happen, the shift of accountability."
Facebook was not immediately available for comment on this story.
Cambridge Analytica is accused of harvesting the data of millions of Facebook users without their permission to influence U.S. voters during the 2016 presidential elections. The company has denied this.
It obtained Facebook data through a quiz app set up by Aleksandr Kogan, a lecturer at Cambridge University. Cambridge Analytica has said no more than 30 million profiles were shared.
Traders mostly ignored bad news out of the hearing, with Facebook's stock rallying significantly. But the company Zuckerberg helped found still faces challenges ahead.