[EdHominem]

They don't need to remove porn though. They could keep a NSFW counter and increment it for every piece of suspected porn you post. If your NSF counter / post count is greater than 0.2, start hiding your posts from people with a low NSFW ratio.

This way, even if they mis-categorize a medical image it won't be banned, just not widely disseminated.

[mattkrause]

Didn't Flickr do something like this? (Once upon a time, before it was re-re-re-re-designed into oblivion)