'The federal law requires website owners to keep records documenting, among other things, that "every performer portrayed in a visual depiction of actual sexually explicit conduct" is over the age of 18.'
I read that as simply "website owners must confirm that pornographic/nude images depict people over the age of 18". Doesn't that mean that as long as the depicted has been confirmed, it's ok to post it? This also goes for posting nude anime content; according to the federal law, it's fine if you have hentai or ecchi or whatever, since it's not kiddie porn in that sense, no matter what is depicted.
Of course, the BBS rule covers most of that, but nude photos seem to be completely ok as long as they follow the federal guidelines...