...because bank characters can't get PP'd in town. Tyran
Unless someone can tell me otherwise, the rules on the forums do not say there is any safe zone against PP. Pvp is even acceptible if you roll in from another zone, but you have to be super careful. The only safe zone would be a protected area where even then it is possible for outsiders to penetrate.
You could have a guy pick your entire mule, and not even be able to kill him (as you would be playing a mule). Doesn't sound like a position I would like to be in.