If you PVP on Alliance anywhere on Battlegroup Ruin (which includes Warsong, Argent Dawn, Lothar and Medivh, among others), you've probably run into Xzin. Most likely, you've seen him very briefly before your untimely death. You may have complained to your teammates about him. Perhaps you reported him to a GM. You could have even created one of the many "@Xzin" threads that litter the Magtheridon realm forums. You can do many, many things, but nothing will change the fact that you are dead. And the next time you see him, you will also be dead.
Xzin plays a team consisting of one undead priest and four undead mages on Magtheridon-US. He runs five separate WoW accounts on five separate computers, controlling the characters through coordinated wireless keyboards. All the arcane/fire-specced mages follow the priest around and do coordinated damage while the holy-specced priest heals them. Any single player who attempts to take on the Zins will be instantly killed.
The Zin Army reached Warlord status a couple months ago, and now Xzin, Azin, Bzin, Czin and Dzin are testing out PvP in the Burning Crusade Beta. WoW Insider caught up with Xzin between Arena bouts and asked him about his unique setup.
(Edited to add video links.)