I found a glitch where I could use a mind control helmet on an enemy
player in PVP and then use eyes of the beast on him to control him
directly. I could then make the guy dance around, use up all his
cooldowns, or in most cases jump off a cliff. I once had a horde run
into Orgrimmar where he was promptly beaten to death by his friends.
Horde have no manners.
The really fun part was I could
disengage it and it would leave its victim helpless and paralyzed. I
had to scatter shot them to regain their controls. But like most fun
glitches, Blizzard had it fixed by the next patch.