Facebook account of data breach disappoints EU commissioner

"Unfortunately some explanations fall short of my expectations. It's clear that data of Europeans have been exposed to a huge risk and I am not sure if Facebook took all the necessary steps to implement change," she noted.

Jourova commented about a letter she received on Thursday by Facebook chief operating officer Sheryl Sandberg.

The commission spokesman said the Facebook letter itself could not be made public.

The letter reportedly explained that data from possibly up to 2.7 million users from the EU may have been "improperly shared" with Cambridge Analytica, a UK consulting firm accused of having used that data in an attempt to sway the US elections and the Brexit vote.

"As I already said, for me this story is not only about data protection," said Jourova on Friday.

"This is a threat to our democracy and electoral processes. I would like to speak with Ms Sandberg about how they intend to ensure transparency and respect the rules of our democratic debate and how they plan to change once the GDPR is in place."

The GDPR is the general data protection regulation, a new piece of EU legislation that is expected to have severe ramifications on the relationship between companies that process personal data and their customers.

"This story is too important, too shocking, to treat it as business as usual," added Jourova.

"The internet is not a space free of rule of law. The rules that apply offline also need to be respected in the online world," she noted.

"Those companies have a great power; I want them to also bear great responsibility," the Czech commissioner said.

Mistakes were made

Earlier this week, Facebook CEO Mark Zuckerberg said in a conference call with press that the company had made mistakes and that it was trying to improve security on the social media platform.

"We didn't take a broad enough view of what our responsibility is. That was a huge mistake. It was my mistake," he said.

"The reality of a lot of this is that when you are building something like Facebook that is unprecedented in the world, there are going to be things that you mess up," said Zuckerberg.

"If we had gotten this right, we would have messed something else up. I don't think anyone is going to be perfect. What I think people should hold us accountable for is learning from the mistakes, and continually doing better and continuing to evolve what our view of our responsibility is," he added.

Next week, Jourova will speak to Sandberg by phone.