Blizzard has issued bans to "several thousand" Diablo 3 players who were using bots, hacking or otherwise cheating.
"We've recently issued account bans to several thousand Diablo III players who were found to be using botting programs while playing," said the developer in a statement.
"In addition to undermining the spirit of fair play, botting, hacking, and other forms of cheating can also cause technical problems with the game as well as contribute to performance issues with the Battle.net service."
It added, "As always, maintaining a stable, safe, and enjoyable online environment for legitimate players is very important to us, and we'll be continuing to keep watch on Battle.net and take action as needed."
The developer also says that it will be "adding the ability for players to report this kind of behavior directly through the game client" in a future patch.
In the meantime, Blizzard points users to this forum thread to report players for cheating.