Its hard to be online 24 hours and moderate even a small forum, it gets worst with large forums. So all those big sites like youtube has flag systems, thumbs down, etc.. for comments or content. So if 20 members (some trusted usergroup) flagged/thumb down a post then it will automatically go to hidden state. Others have to click the warning message and see the content which is flagged by the community members. Or we can soft delete the post until a real moderator check it. I think this is an essential feature. Already all the large sites like youtube using it.