Vitale and co-defendant Todd Moeller were in contact with a government confidential informant via instant messaging, and agreed to send spam advertisements for a product in exchange for half of the profits, Garcia said in a statement. The pair then sent about 1.2 million unsolicited e-mails to AOL users between Aug. 17 and Aug. 23, 2005. They changed the headers on the e-mails and used various computers to conceal the source of the spam.

Vitale, 26, resides in Brooklyn. Sentencing is scheduled for Sept. 13 before U.S. District Judge Denny Chin, who presided over the criminal case, in Manhattan. He faces a maximum sentence of 11 years in prison and a fine of US$250,000, or double the maximum gain or loss resulting from the offense. Moeller, a New Jersey resident, will stand trial for the same charges.

One observer felt the legal victory was somewhat hollow.

"I think this is a moral victory for AOL, but not much else," said Adam O'Donnell, director of emerging technologies at Cloudmark. "The economic motivations underlying abuse mean some other spammer has already taken his place, and it is likely the spammer's replacement is coming from outside American jurisdiction."