A Squirrel Hill man is accused of using the "Casual Encounters" section of Craigslist.org to solicit what he called "family fun."
A Columbus, Ohio, man is accused of pimping out two women for prostitution on the Web site's "Erotic Services" section.
As has been happening across the country, law enforcement officials in Western Pennsylvania are now turning to the popular classified ad site to find criminal activity.
Already, prostitution operations using Craigslist have been exposed in Seattle, Jacksonville, Fla., Cook County, Ill., and Garden City, N.Y.
It is yet another example of how the Internet is changing not only the way crimes are committed, but how law enforcement conducts its investigations.
Craigslist -- a site where its users can find anything from concert tickets to used furniture to a hot date -- was founded by Craig Newmark in San Francisco in 1995. He started it as a hobby, listing events happening around the city. Since then, it has evolved into a worldwide service available in 450 cities and more than 50 countries.
According to company officials, Craigslist has 30 million users each month who post more than 25 million listings.
"Many sites that have been successful are interactive, highly social and meant to be unmoderated," said John Palfrey, the executive director of the Berkman Center for Internet & Society at Harvard Law School. "The people who run them aren't in the business of scanning posts when they go up.
"The scale is so great, it would be literally impossible to screen everything before it gets posted."
Which is why, for Craigslist, the company relies on the community to moderate the site, spokeswoman Susan MacTavish Best said.
If a user finds an inappropriate posting, it can be flagged, and if enough people flag it, the post will be removed.
But sometimes, the questionable listings aren't flagged -- for instance, the one police say Brian Lee Nestor posted back in September.
According to an affidavit filed in his case in federal court, Mr. Nestor, 44, of Squirrel Hill, put a listing under Craigslist's "Casual Encounters" section.
It read: "Anybody into family fun?" followed by, "bring your son and hang out with us."
A Greensburg police officer who handles computer crimes for the jurisdiction found the ad on Sept. 9.
He responded to the posting, saying that "Family fun sounds great, reply with age, limits, a photo would be great."
The police officer and Mr. Nestor corresponded through e-mail for several days. According to the affidavit, Mr. Nestor, who also solicited child pornography, became frustrated: "Look I'm tired of these endless e-mails. ... I'm just looking to get with a boy discreetly."
In one exchange, Mr. Nestor, who was previously investigated by the FBI but not charged for having thousands of images of child pornography on his computer, wrote that when they met, the two men would have to expose themselves to each other to ensure that neither was a cop.
He was arrested Sept. 14 and charged with coercion and enticement, as well as possession of child pornography. Mr. Nestor's arraignment is scheduled for Tuesday.
Supervisory Special Agent Bill Shore, of the Pittsburgh FBI's computer crimes squad, said that criminal behavior online constantly evolves.
It started out with news groups and chat rooms and e-mails, later leading into instant messaging and advertising services such as Craigslist.
"It's a new outlet," Mr. Shore said. "It's been happening historically in all those other forms of communication. It's now morphed into this."
Even though under the federal Communications Decency Act, the publisher of an online forum cannot be held responsible for what is said there, officials with Craigslist have been extremely cooperative with law enforcement when crimes are discovered, Mr. Shore noted.
A recent viewing of the Craigslist personal ads subset "Casual Encounters" section in Pittsburgh showed 719 posts.
Often, the people advertising there are seeking a partner for casual, or NSA -- No Strings Attached -- sex.
There were a few offering "massages," as well as one woman who was offering her feet for hire at an hourly rate.
Another woman had a listing entitled: "Looking for a man to buy my underwear." Her ad noted that she accepted both online payment and money orders.
Under Pittsburgh's "Erotic Services," section, everything from dancers to massage to strippers were offered for sale.
Despite differences in personal taste, none of those listings would violate the law because they are exchanges regarding activities between, presumably, consenting adults.
"If someone is simply looking to meet another person, regardless of how offbeat their interests are, that's not illegal," said U.S. Attorney Mary Beth Buchanan.
Postings become criminal, though, when children are being exploited or money is being exchanged for sex.
That's where Morris Hill, 30, of Columbus, Ohio, got into trouble, when he posted ads on Craigslist in April offering prostitution.
On Friday, he pleaded guilty in federal court in Pittsburgh to transportation with intent to engage in prostitution, and inducement, enticement and persuasion of prostitution.
According to Assistant U.S. Attorney Scott Brady, Mr. Hill brought one woman to Pittsburgh from Parkersburg, W.Va., and another from Colorado, to work for him as prostitutes.
Though the woman from Colorado knew what Mr. Hill expected of her, the one from West Virginia says she did not.
Instead, she told police that though she had just met him, Mr. Hill convinced her to come to Pittsburgh by telling her "that he would buy clothes for her, pay to have her nails done and wanted to develop a romantic relationship with her."
Mr. Hill, however, turned both women into prostitutes. He posted listings on Craigslist to get them clients, including in the ads a cell phone number to contact the women, and prices -- $150 per 30 minutes or $220 per hour.
The prosecution said the women were seeing from five to 12 clients each day.
Mr. Hill was caught when an Allegheny County District Attorney's Office task force noticed him driving back and forth to a number of hotels in the area in a pewter Hummer.
Task force officers suspected Mr. Hill was involved in the drug trade, but when they questioned the women, who both said Mr. Hill had physically assaulted them, they learned about the prostitution.
Mr. Hill will be sentenced before U.S. District Judge Terrence F. McVerry on Jan. 18.
Mr. Palfrey, the law professor from Harvard, believes that crimes such as those being conducted online will continue to grow because there are too few law enforcement resources available to battle them in the changing digital world.
"The crimes are of such a scale and so spread out, it's too difficult to get it done effectively," he said. "It's not that law enforcement can't catch the bad guy, it's that there are too many of them for the good guys to pursue."
Correction/Clarification: (Published Oct. 16, 2007) The classified advertising Web site is craigslist.org. A headline this story as originally published Oct. 15, 2007 listed it incorrectly.
First Published: October 14, 2007, 4:00 a.m.