The FBI has launched an investigation into the "Here you have" worm, which disrupted corporate e-mail systems in the U.S. two weeks ago. A hacker using the name Iraq Resistance has exchanged a number of e-mails with IDG over the past two weeks discussing the incident.

"Here you have" was a big deal in North America, temporarily gumming up e-mail systems in large organizations such as Disney, Proctor & Gamble and NASA. On the day it was unleashed it accounted for between 6 percent and 14 percent of all spam on the Internet