Ireland's data regulator has launched an official inquiry into Facebook after details on 533 million users were leaked on a hacking website, a spokesman said Wednesday.
The Data Protection Commission (DPC) said the probe was launched to determine whether the EU-wide GDPR charter on data rights and the corresponding Irish legislation had been -- or is being -- infringed by Facebook.
The US tech giant said it is "cooperating fully" with the regulator's enquiry, which it added "relates to features that make it easier for people to find and connect with friends on our services".
"These features are common to many apps and we look forward to explaining them and the protections we have put in place," a company spokesman said.
Earlier this month a trove of information about more than 530 million Facebook users was shared on a hackers' forum.
Facebook has previously said that the data was "scraped" from the site by hackers in 2019, who took advantage of a feature designed to help people easily find friends using contact lists.
In its statement, the DPC said it had been in touch with Facebook Ireland over the issue and the company had sent "a number of responses".
The DPC believed that Facebook might have violated "one or more provisions" of Ireland's data protection laws, or the EU charter, or both, it added.
Facebook's European headquarters is the Irish capital, Dublin, and the DPC acts as the firm's lead regulator in the EU.
Under the landmark General Data Protection Regulation (GDPR), which came into effect in 2018, social media users have a wider range of rights relating to their data.
Regulators such as the DPC have been armed with new powers including the ability to fine firms up to four per cent of their annual global turnover.