Sometimes during a game you can gate approached by a player who says he is friendly, as soon as you turn around he shoots you in the back or axes you to death. What I suggest is that according to players actions there should be certain tags on, such as if a player have a lot of murders he would be tagged as bandit and probably will get shot by other players. If a person have a lot of bandit kills he could be tagged as bandit hunter or bounty hunter, this could improve trust between players and I don't think it affect realism because in other words its called reputation or a player.