BERLIN, March 22 (Reuters) - Germany's justice minister Katarina Barley has asked Facebook to clarify whether the personal data of the social media site's 30 million users in the country were protected from unlawful use by third parties, according to a report in the Funke group of German regional newspapers.
Barley, in remarks published on Thursday in the newspapers, said Facebook's management in Europe must explain to the German government how data of millions of American Facebook users reached Cambridge Analytica, a consultancy hired by U.S. President Donald Trump for his 2016 election campaign.
"The question of what happens with the data of 30 million German users is a central issue of consumer protection," she said.
The justice ministry could not be reached for comment.
Barley has summoned Facebook for talks at the justice ministry. She did not say when the meeting would take place.
She also said it was unacceptable that social media users "are spied on in order to be targeted with election ads or bombarded with hate messages against political rivals."
Clear rules were needed to prevent such misuse of user data, which poses a threat to democracy, she said in the newspaper report.
Facebook has been rocked this week by a whistleblower who said Cambridge Analytica, which Trump hired for the 2016 campaign, improperly accessed information on Facebook users to build detailed profiles on American voters.
The revelation has knocked nearly $50 billion off Facebook's stock market value in two days and hit the shares of Twitter and Snap over fears that a failure by big tech firms to protect personal data could deter advertisers and users and invite tougher regulation.
A former Facebook operations manager told a British parliamentary committee on Wednesday that data harvesting of member profiles by outside software developers was once routine and that the company took years to clamp down on the practice.
Facebook declined to comment directly on the testimony of the ex-employee, Sandy Parakilas.
In announcing the suspension of Cambridge Analytica and related researchers from Facebook late last week, it said it now requires app developers to justify any data they collect and how they are going to use it
"In the past five years, we have made significant improvements in our ability to detect and prevent violations by app developers," Facebook said. (Reporting by Joseph Nasr Editing by Douglas Busvine and Jane Merriman)