They should just follow Runescape's lead with grief, it handled it pretty well. 9/10ths of the game is a mildly competitive borefest with no player-to-player interaction and the rest is an terror-filled wasteland with anything-goes rules. The players who like everything to be 'fair' can rest assured that they aren't missing anything because most of the content is in their territory. There's a little bit of something for everyone.