The Register is reporting on the takedown of a botnet once responsible for 1/3 of the world's spam. The deed was done by researchers from the security firm FireEye, who detailed the action in a series of blog posts. PC World's coverage estimates that lately the botnet has accounted for 4% of spam. From the Register: "After carefully analyzing the machinations of the massive botnet, alternately known as Mega-D and Ozdok, the FireEye employees last week launched a coordinated blitz on dozens of its command and control channels. ... Almost immediately, the spam stopped, according to M86 Security blog. ... The body blow is good news to ISPs that are forced to choke on the torrent of spam sent out by the pesky botnet. But because many email servers already deployed blacklists that filtered emails sent from IP addresses known to be used by Ozdok, end users may not notice much of a change. ... With [the] head chopped off of Ozdok, more than 264,000 IP addresses were found reporting to sinkholes under FireEye's control..."