Here is how it should work: certain classes(lets say Smuggler and Agent) have this "pickpocket" ability which they can use on any playable character. If the ability fires successfully, they get a random piece of loot that is auto-generated by the game. To be clear, this is NOT taken from the other player's inventory, it is just a random loot roll.
HOWEVER(and here is the fun part), if the ability fails, then the smuggler or agent gets their PvP flag turned on for the person they were targeting, and the person they were targeting gets first attack if they choose to attack. If they do not want to attack, then they can just ignore it and go about their business.
It would have to be all classes though, I mean if its only certain classes the rest will get angry about it and people will just say dumb crap like "screw you biofail" for implementing it.