More than 800,000 Facebook users were affected by a software bug that temporarily unblocked people they had previously blocked. The bug in both Facebook and Messenger had unblocked users, allowing them to see some content that the affected Facebook user had posted.
"Someone who was unblocked could not see content shared with friends, they could have seen things posted to a wider audience,” Facebook explained in a blog post. “For example, pictures shared with friends of friends. We know that the ability to block someone is important — and we'd like to apologise and explain what happened.”
The issue reportedly affected some users between May 29 and June 5, 2018, and has since been fixed. According to Facebook, the glitch did not reinstate any blocked persons or severed friend connections on the social network.
The social media giant said it became aware of the bug on May 31, but took until June 5 to restore the blocks.
Facebook stated that 83% of people affected by the bug had just one person they had blocked temporarily unblocked. The company has notified affected users encouraging them to check their blocked lists and check their settings.
“It then took us some time to do the due diligence that we had the right number of people impacted and to build the notification messages + get translations done. (It affected people globally),” Facebook’s Chief Privacy Officer Erin Egan said.
The incident comes as Facebook continues to deal with the aftermath of the Cambridge Analytica scandal. The social media girm revealed that the data firm gained unauthorized access to up to 87 million users’ data, mainly in the United States - up from the previously reported 50 million users.
Facebook said it had shared data with 61 hardware and software makers and has since vowed to do more to “keep people informed” and take steps to “put people more in control of their privacy.”