One of the best MMO games I\'ve played was a space sim called Jumpgate. I personally think they got the PvP system down real well. Anyone can kill anyone else, but they had a couple of systems implamented to stop idiots from killing random people who didn\'t have PvP indicated. The first system was a political rating. The more missions you do, NPC\'s you kill (there were no GOOD NPC\'s so that was fine) the higher your political rating, and the higher the political rating the lower the Taxes you paid on your purchases. The other system was a bounty system, that placed a nice fat bounty on your head the moment you killed a non NPC, which was announced publicly over the Main com channels, so that every bounty hunter worth his level was chasing the person down. The nice side effect was that some of the \"unregulated\" stationstended to be populated with the rougher element of the game, which noobs very quickly learned to avoid, but the rest of the areas were very safe. In the whole time I was playing I never saw someone shooting down a non PvP player in regulated space.  Something like this could easily be ported over to this game.