Another essay to read on the subject is "Attacked from Within" http://www.kuro5hin.org/story/2009/3/12/33338/3000 http://www.kuro5hin.org/story/2009/3/12/33338/

Another essay to read on the subject is "Attacked from Within" http://www.kuro5hin.org/story/2009/3/12/33338/3000 http://www.kuro5hin.org/story/2009/3/12/33338/3000 . I think the main reason is that communities grow only so big and then they turn into a society. Users recognized in a community will lose their recognition that evaporates into the mediocre society.