From itsecuritynews.info
Recently Facebook encountered quite a bug crisis, as a bad code update going live on the night of 10th January apparently prompted the exposure of the mysterious anonymous of admins and many known personalities for a few hours.
All it took to exploit’ the bug was opening a target page and checking specifically the edit history of a post and Facebook erroneously showed the account or accounts that made those edits to each post, as opposed to simply displaying the edits themselves.