] Gangs based in Eastern Europe have been found to have
] been launching waves of attacks on corporate networks
 . . .
] The attacks involve gangs commandeering as many as hundreds of
] computers through hacking methods to use without their owners'
] knowledge. A command is then issued to each one simultaneously to
] make a series of bogus requests to the servers of the victim. The
] weight of traffic brings the servers to a halt and legitimate
] requests to carry out transactions cannot be completed.

This ties in to one of my speculations about the origin of some of the recent "let's build a clone-army" worms.

Eastern European Hackers Using DDOS Attacks to Blackmail Companies