An upstate New York teenager became the first person arrested in the United States for sending spim, or unsolicited instant messages, last week following a sting operation at Los Angeles International Airport.

Anthony Greco, 18, of Cheektowaga, N.Y., was charged with violating the CAN-SPAM Act, threatening to cause damage to computers with the intent to extort and causing damage to a protected computer. If convicted of all three offenses, Greco faces a maximum possible penalty of 18 years in federal prison.

Greco is accused of sending approximately 1.5 million spim messages to the users of Los Angeles-based MySpace.com, an online community catering to teenagers. The unsolicited messages were mostly advertisements for mortgage refinancing and adult pornography.

According to the U.S. attorney for the central district of California, after Greco sent the spim, he contacted MySpace officials, took responsibility for the spim flood and proposed he be given exclusive rights to send commercial messages to MySpace users. He also offered to protect MySpace.com against other spam advertisers for $150 per day.

When MySpace did not respond, Greco threatened to show other advertisers how to send messages to MySpace.com users. In his messages, Greco noted that sharing his knowledge would "open a Pandora's box of spam" on MySpace.com's computer system and potentially take MySpace.com offline.

The threatening e-mail eventually led to several telephone calls between Greco and MySpace. Greco agreed to travel to Los Angeles to further discuss the matter. Upon landing in Los Angeles on Feb. 16, he was arrested by members of the U.S. Secret Service and the Los Angeles Police Department.

After a detention hearing Thursday morning, Greco was released on $25,000 bond. His next court appearance will be a March 21 arraignment in Los Angeles.

Like spamming, spimming involves sending messages to users without their consent. While spam is sent to e-mail inboxes, spim specifically targets instant messages or chat room users.

According to a recent survey by the Pew Internet & American Life Project, almost a third of all instant message users have received spim. Pew said that translates into approximately 17 million Americans.

The Pew survey results show that younger Internet users are most likely to use instant messaging and, therefore, are the most likely users to receive spim. Fully 39 percent of those under 30 who use instant messaging have gotten spim. By comparison, 27 percent of the IM users between 30-49 have gotten spim.