I don't really like alignment systems either.
Have a look at Salem (by the guys who made Haven & Hearth):
It features unrestricted PvP with full loot and perma-death. Every crime leaves behind a "crime scene". If a player investigates it, the criminal can be tracked down and dealt with one way or another. You can even lynch criminals while they are offline.
Just to clarify, I'm not arguing for perma-death, although I wouldn't mind it, either. Anyway, the system just needs some kind of punishment.
Known for its controversial permanent death feature, an essential game mechanic that introduces risk as players progress in the new world, Salem is a fresh twist on the MMO genre giving players control of their towns in the game and introducing frontier justice in the open Player-versus-Player (PvP) environment.
The concept of revenge and towns policing themselves and even sanctioning hits on griefers is going to be a really compelling aspect. We know we'll see some interesting things when the community finally has a chance to play Salem later this year.