This video of the David Cerny sculpture, "Piss," has just gotten me into all sorts of trouble over on flickr. Since I didn't think to flag it as "restricted," they removed it, flagged every image in my stream as restricted, and took away my ability to adjust the privacy settings on any of my work.
The community guidelines DO require you to flag full frontal nudity as "restricted."
The yahoo guidelines strictly forbid (whether marked "restricted" or not) any "sexualized" images of urination. (???)
You'd have to posses a pretty special imagination to feel that I had crossed any lines.
I'm hoping that maybe the gang over here at Vimeo are a little less puritanical.
My request to have my account reviewed has not yet gotten any sort of response.