Few firms have been hit as hard as Blizzard, however. Cheats granting players near-infinite abilities essentially melted online play of Diablo, the company's 1997 Dungeons-&-Dragonsesque hit. Determined not to repeat the mistake, Blizzard banned 8,500 players of Diablo II earlier this year.

Yup, hacks ruined Diablo2's economy as well.. and when hackers are ruining games, they are probably hurting word of mouth sales at least a bit I'd think. Hackers are poo heads.