According to survey released Wednesday, nearly one third, or 17 million, of the nation's instant message users have received some kind of unsolicited message at least once.

The Pew Internet and American Life Project contacted respondents by phone over a period from January 13 to February 9. The study, however, did not include those under 18, which is widely considered the biggest group of IM users.

"The people who brought you spam...are trying to figure out whether this is a cash cow," Pew Internet Executive Director Lee Rainie said in the report. "It's an iron law of modern capitalism that wherever people are gathered, commercial messages will eventually intervene."

According to various studies, IM spam, or "spim", is indeed increasing. Data from IMLogic suggests that spim went from practically zero in 2003 to 5 percent of all messages sent in 2004. The group believes this number could rise to 8 to 10 percent by the end of 2005.

The content of spim messages vary, from scams similar to those in spam e-mail to hackers trying to gain access, or to spread viruses. Some spim will even be of a sexual nature.

Both AOL and Microsoft are working on ways to combat spim on their services. For now, users can combat spim by using the feature in both networks' software to restrict who can contact them.