If you block someone on Facebook, you probably want them to… you know, stay blocked. At least unless you say otherwise.
Facebook has just disclosed that around 800,000 users were impacted by a bug that silently unblocked “some” people they had blocked.
The bug was live from May 29th until June 5, the company says.
Worth noting: the bug didn’t go so far as to make the would-be blocked individual your friend (even if they were your friend prior to the block), so anything an affected individual might’ve posted to a friends-only audience should have remained private. It would, however, allow a blocked user to do things like contact you on Messenger, or try to re-add you as a friend.
While Facebook isn’t saying much about what caused the bug, they’re sending out a notification (pictured above) to anyone they believe was affected.
Update — Facebook has shared some more details about the cause of the bug with TechCrunch’s Josh Constine via Twitter.