Wall Street Journal: According to security firm Symantec, the Rustock botnet is responsible for half of all spam and is the largest botnet in the world. Make that "was" the largest botnet in the world, because Microsoft and federal agents believe they may have shut down Rustock for good.
In an attempt to "decapitate" the botnet, U.S. marshals and Microsoft employees seized servers from hosting facilities Kansas City, Mo.; Scranton, Pa; Denver; Dallas; Chicago; Seattle and Columbus, Ohio. Microsoft alleged that those servers were being used as "command and control" systems to control the botnet. "We think this has been 100% effective," said Microsoft's Richard Boscovich.