Microsoft's Digital Crimes Unit, working with federal law enforcement agents, has brought down the world's largest spam network, Rustock. Rustock, at its peak, was a botnet of around 2 million spam-sending zombies capable of sending out 30 billion spam email per day. Microsoft's wholesale slaughter of Rustock could reduce worldwide spam output by up to 39%. Rustock was taken down, piece by piece, in a similar way to the Mega-D botnet. First the master controllers, the machines that send out commands to enslaved zombies, were identified. Microsoft quickly seized some of these machines located in the U.S. for further analysis,...