What really happened?
Members of a body building forum first spotted the bug, which appeared in a new feature that allowed people to report multiple instances of inappropriate content simultaneously. If you reported a photo for reasons of “nudity or pornography,” you were given the option to “take action by selecting additional photos to include with your report”. You were then shown additional recent photos from the same profile to flag if inappropriate. Unfortunately, photos were shown regardless of their owners’ photo privacy settings.
This blunder resulted in private photos of Facebook CEO Mark Zuckerberg's to be released (Source: here).
» Facebook Bug Revealed Mark Zuckerberg’s Private Photos | Mashable