Diablo III's auction house, you are the stuff of legends.
Late last night, Blizzard took Diablo III's auction house offline to deal with a gold duplication bug that was discovered to be exploited by players. All gold trades were halted at the time, and Blizzard had a patch in place within 30 minutes.
But it's the later update that concerned many D3 fans as Blizzard announced that it wouldn't be rolling back the server, but instead, dealing with each individual offending account on a case-by-case basis. This is more time-consuming for the dev team, but has much less of an impact on the community as a whole.