If you use the item "Cenarion Beacon", buyable from Cenarion Expedition, it will summon a "personal cenarian guard" so to speak. Trick is, this will attack opposite faction, and if you are in a city (at least at the expedition), the guards will then attack the "personal guard", NOT you. The enemy player will loose 125 reputation when the "personal guard" dies.
Might sound a little confusing...but it works :<
Might sound a little confusing...but it works :<