Recently a site very similar to this one was shut down. I don't know the details, but rumors are pictures of underage girls had been posted, possibly stolen from Facebook accounts.
Rule 6 states you cannot post private pictures. Pictures easily found on the internet are fair game, such as celebrities or just sites with pictures such as the popular Imgur.
Trolling of Facebook for private pictures is not OK. Neither is taking a pic of someone with your phone and uploading here. It's almost certain that person would not want their picture on a rape fantasy site. Pictures of obviously underage kids will certainly be removed even if clothed. And a violation of Rule 1 of posting unclothed pictures of underage kids will get you reported to law enforcement.
A while back someone posted pictures of his friend's girlfriend talking about his fantasies about her. I asked him several times if she knew those were here without him answering. I let it slide, until a few days ago I went in and deleted all those pictures.
I can see where it may seem harmless, so I'll give warnings when I see it happen (and delete the pictures). But repeated offenses will mostly likely get the person banned. People deserve some privacy, and here they will get it.