No permission is needed
I was ridiculed on The Reg the other week after trying to explain this very problem - to a person who didn't even have a Facebook account.
No permission is needed - as things currently stand - to post content such as photos of other people - on to Facebook.
As a case in point I uploaded a photo of Paris Hilton to my Facebook account, with various captions. Now, unless someone "reports" that, it will remain there forever. Paris and I didn't have a conversation when I uploaded it, no consent was implied or required. And so it will remain there, even with defamatory words on the image etc etc etc. She isn't tagged (we're not "friends" of course) so I doubt she even knows it's there.
This is one situation where legal intervention would be useful. As it stands, I can post something horrible about you - or anyone else - on FB, and unless it's reported - or even known to be there - it will remain there, for all to see.
The onus is on the person who's pissed off to report it, and then fight for its removal.
Oh, and just so everyone doesn't downvote me this time - I'm not suggesting I think the way it works is acceptable. Far from it.