Saw on Voodoo Extreme that Battle.net have closed 36,000 Diablo II accounts due to cheating:

"We have just closed more than 36,000 accounts for cheating on Battle.net. More than 28,000 CD keys tied to these accounts have been disabled from Realm play on Battle.net for one month, and more than 3,000 CD keys have been permanently disabled from Realm play due to repeat offenses. Please see the Battle.net FAQ for details on our anti-cheating procedure. As a reminder, the Battle.net news window that Diablo II players see after logging in has had a long-running warning against the use of hacks, clearly indicating that if we detect that cheating is taking place, the offending accounts may be closed without notice and the CD keys tied to these accounts may likewise be disabled without notice. Today’s account closures reflect our zero-tolerance policy against cheating, as well as our effort to prepare the Realms for the new ladder season. We appreciate the support of the thousands of legitimate Diablo II players in helping us keep Battle.net a secure and fun place to play Blizzard games."