Cook County, Ill., Sheriff Tom Dart is suing the popular classifieds site craigslist, saying the Web site has become the hub for Internet prostitution.
"The problem is that they are actively facilitating the commission of a crime ... and it's not the consenting-adult prostitution," Dart tells NPR's Robert Siegel. "We're talking quite frequently about juveniles being involved here."
"I've told them, you've got a great site for 99 percent of it, but there's one part of it that (A) is illegal, but (B) is causing people to be victimized, primarily women," Dart says. "I've asked them: I've said either shut it down or monitor.
"They will do neither of them. And that's the thing that's perplexing to me."
Craigslist compares the ads to those found in some newspapers, alternative weeklies and the Yellow Pages. The Web site says it gives the money it earns from the section to charity and enables users to flag inappropriate material.
Dart says that the flagging is being done mainly by prostitutes who are trying to knock off other prostitutes' ads.
"The money they are donating to charity I find to be somewhat comical and very sad because here they are getting money quite often from people who are either juvenile pimps or into human trafficking and the money is subsequently being given to people to prevent juvenile pimping and human trafficking," Dart says.
Dart says ads on craigslist contain naked or seminaked photographs with prices included depending on the type and duration of the act.
"It's not allowed in any newspaper that I've ever seen," he says.
Dart, however, is realistic about what he expects from the lawsuit.
"I have no delusions that we're going to change a crime that's been around since history has begun, but we know this has become a hub of it. ... We're not trying to be prudes here, but just do not help facilitate crimes."