TIGARD, Ore. – In the last three months, undercover Tigard police officers have busted 16 people for prostitution based on arrangements made over the Internet.

The operation led officers into everyday neighborhoods where people would not normally expect to find prostitution occurring.

Among those arrested was 22-year-old Shanelle Carlson, who is accused of twice forcing a 15-year-old girl to work with her at the Motel 6 in Tualatin. Carlson also faces charges in connection with photos taken of the teen and an advertisement for the girl posted on Craigslist.

The use of such Web sites as Craigslist, MySpace and Facebook as well as cell phones and text messaging is helping push prostitution into neighborhoods, officers say.

Prostitutes are selling their services directly to johns online, eliminating the middle man, or pimp, and putting themselves at a different type of risk.

They are making themselves very vulnerable because they don't know the history of the place they are going or the person they are encountering, said Jim Wolf, a Tigard police spokesman.

"It's very dangerous," he said.