Out of the terrible darkness that brings forth monsters like MyDoom e-mail worm, MyDoom.O,"DoubleClick Inc. suffered a DDoS (distributed denial of service) attack Tuesday that knocked out its popular online ad-serving service and its own corporate Web site for several hours, the company has confirmed."

The company's DNS infrastructure, which provides the means for computers to be refered to by names, and on which many other services crucially depend, was "under a denial-of-service attack from outside sources." - eWeek.