Perhaps another rollback.

Well its not like a Meso exploit which is hard to track down. Nexon Just need to shut down the servers and Delete any item Duped by the same person and voila!

RollBack its not Unlikely but only if it got WAY out of hand.

Well, the problem now becomes that if people are indeed duping items, they'll be trying to sell them off for a much lower profit than if it were a real item. If you see 19 att SCG for 150m, wouldn't you buy it? Then it becomes less black and white than duped item removal.