This is always fun to do on somebody of your own faction after they've pissed you off, since you can't kill them. Wherever they're grinding at, it must be a place where its somewhat crowded with other mobs. Once they attack a mob and they get the tag (as in you can't loot it after it dies) use fear on the mob and if they run in agro range of a nearby creature, that creature will train to THEM and not you. Then when he has both of them on him, use howl of terror to fear them BOTH in hopes they each pull an additional mob making FOUR of them attack him.
I did this awhile ago on my warlock when he was in his 30's, was done in the Yeti Cave in hillsbrad and worked like a charm. He eventually got the idea and apologized for all the transgressions he made to me.