The news: The personal data of 533 million Facebook users in more than 106 countries was found to be freely available online last weekend. The data trove, uncovered by security researcher Alon Gal, includes phone numbers, email addresses, home towns, full names, and birth dates. Initially, Facebook claimed that the data leak was previously reported on in 2019 and that it had patched the vulnerability that caused it that August. But in fact, it appears that Facebook did not properly disclose the breach at the time. It only finally acknowledged it on Tuesday April 6 in a blog post by product management director Mike Clark.
How it happened: In the blog post, Clark said that Facebook believes the data was scraped from people’s profiles by “malicious actors” using its contact importer tool, a feature which uses people’s contact lists to help them find friends on Facebook. It isn’t clear exactly when the data was scraped, but Facebook says it was “prior to September 2019.” One complicating factor is that it is very common for cyber criminals to combine different data sets and sell them off in different chunks, and Facebook has had many different data breaches over the years (most famously the Cambridge Analytica scandal).
Why the timing matters: The General Data Protection Regulation came into force in European Union countries in May 2018. If this breach happened after that, Facebook could be liable for fines and enforcement action, as it failed to disclose the breach to the relevant regulators within 72 hours, as the GDPR stipulates. Ireland’s Data Protection Commission is investigating the breach. The timing is also significant in the US, because Facebook signed a deal two years ago which gave it immunity from Federal Trade Commission fines for breaches before June 2019, so if the data was stolen after that, it could face action in the US, too.
How to check if you’ve been affected: Although passwords were not leaked, scammers could still use the information for spam emails or robocalls. If you want to see if you’re at risk, go to haveibeenpwned.com and check if your email address or phone number have been breached.