And images of vulnerable populations (e.g. kids, animals, retarded people) should be given special consideration. If, for instance, someone posted a "hidden camera" clip from dateline about mental patients being abused or something similar for discussion, I wouldn't have a problem with that. But, if someone posted an amateur video of two 12-year-olds having sex that would need to be removed.
Again, I think that each situation would present unique challenges and should be decided on an individual basis.