I would bet that any legal standard would involve phrases like "good faith attempt" and "standard of practice". (If you find a circle of Nazis up-voting each ot

I would bet that any legal standard would involve phrases like "good faith attempt" and "standard of practice". (If you find a circle of Nazis up-voting each other, you'll have to think up a new moderation scheme.) FaceBook and Twitter are decent examples---their moderation systems are pretty hit-or-miss, assuming good faith.