The first criminal action has been taken against someone accused of sending spam messages over instant messaging software.

New Yorker Anthony Greco was arrested at Los Angeles International Airport last week and charged with sending out unsolicited messages under the CAN-SPAM Act. The 18 year-old sent over 1.5 million instant messages advertising mortgage refinancing services and adult pornography to users of MySpace.com's IM service, according to a statement released by US Attorney Debra W. Yang.

The news comes on the heels of a new survey, from Pew Internet & American Life Project, which reports that approximately 17 million adults have received so-called spim.

In the Greco case, the authorities allege that, starting in October 2004, Greco fraudulently created thousands of accounts at MySpace, an online community in which members can write Web logs, share pictures and send instant messages. Greco then sent spim messages from the accounts, it is said.

However the young man then allegedly contacted MySpace.com and demanded he be given exclusive rights to send commercial e-mail to MySpace.com users. When MySpace.com did not respond, he threatened to share his technique for sending spim messages to MySpace.com users with the spamming community and "open a Pandora's box of Spam" on MySpace's network, the statement said.

The US Secret Service and Los Angeles' Electronic Crimes Task Force then started investigating the case.

Prosecutors are charging Greco with threatening to cause damage to MySpace.com's computers and with intent to extort, in addition to the CAN-SPAM Act violations. He faces a maximum penalty of 18 years in prison if convicted on all three offences.

Greco's case may be the first criminal case brought against a spimmer, but it is not the first spim case to make it to the courts. In October, AOL filed suit against 20 "John Does" in a case that alleged violations of the CAN-SPAM Act for sending bulk IM solicitations over its IM network.

Those cases are sure to be followed by more, if the results of a new survey by the Pew Internet & American Life Project are to be believed. Its survey of 2,200 adults suggests that IM use is widespread.

Around 42 percent of the US' 134 million online adults use IM, it found. Thirty percent of them, or an estimated 17 million adults, have received spim, according to a Pew statement.