Botnets pose a big threat because they can include thousands or tens of thousands of computers all over the world, whose owners don't even know they are comprised. With so many machines spreading malware or spam, themselves spread out over a large geographic area, they can do a lot of damage in a short period of time and they are notoriously difficult to thwart. But Microsoft might be big enough to take them on, and a U.S. federal court has given the company the go-ahead to do it.
Microsoft was granted a court order this week that will require Verisign to shut down the Waledac spam botnet's 277 .com "command and control" domains. This would cut off the connection between the botnet owners and the zombie computers that they control.