Laws written long before the dawn of the Internet age have authorities across the nation struggling to prosecute online prostitution rings because of huge loopholes and defense lawyers' claims that the websites are protected speech.
A case in point is a recent New Mexico case involving a retired professor and former college administrator who were accused in what police described as an extensive multistate, online prostitution ring, experts say.
The two were cleared after a judge ruled that state law said the website they operated didn't constitute a "house of prostitution," even though investigators said the men used the site to recruit prostitutes and promote prostitution.
The problem, legal experts say, stemmed from law enforcement officials trying to apply old prostitution laws in a high-tech world. And they say it happens in many states, with authorities struggling to prosecute websites as "brothels" or pinpoint where free speech ends and the facilitation of a crime begins. Further, the National Conference of State Legislatures says state legislatures aren't actively working to update prostitution laws.
"Sometimes states' laws are too specific and were written years ago, long before the Internet," said Scott Cunningham, a Baylor University economics professor who has written about technology and prostitution. "That's why we are seeing some successful challenges to laws when websites are involved."
A big reason: Many websites function as screening services linking would-be prostitutes with potential customers, Cunningham said. That isn't enough to charge website owners of a crime in some states.
Another barrier for states is a 1996 federal law that offers cover for some website owners by protecting them from third-party content, experts say.
In the New Mexico case, a judge ruled in June that a website linked to two men accused of helping run an online prostitution ring was legal.
The ruling was a blow for prosecutors, who were preparing to present to a grand jury their case against former University of New Mexico president F. Chris Garcia and David C. Flory, a retired physics professor at Fairleigh Dickinson University in New Jersey. The two were accused of helping oversee a prostitution website called "Southwest Companions."
Investigators said the prostitution ring had a membership of 14,000, including 200 prostitutes. Members paid anywhere from $200 for one sex act to $1,000 for a full hour. Prostitutes were paid with cash, not through the website, according to police.
But State District Judge Stan Whitaker ruled that the website, an online message board, and Garcia's computer account did not constitute a "house of prostitution." Whitaker also said the website wasn't a "place where prostitution is practiced, encouraged or allowed."
Garcia, Flory and others were arrested in June 2011 on a criminal complaint charging them with promoting prostitution. Flory, who has a home in Santa Fe, bought the site in 2009, prosecutors said. He was identified by police as the ringleader; Garcia was accused of recruiting prostitutes.
"We have long maintained that Mr. Garcia did nothing illegal," said Robert Gorence, Garcia's attorney. "He feels vindicated by the judge's decision."
Flory has declined to comment.
The ruling sparked Gov. Susana Martinez to call for state legislators to look at updating New Mexico's prostitution laws to include websites.
In Florida, authorities in 2002 set up an elaborate sting to shut down a Tampa-based escort-ad site called Bigdoggie.net by using undercover officers who set up fake ads. Investigators said the website connected customers to escorts and published reviews on escorts.
But prosecutors' efforts to conceal informants' identities failed, and a judge dismissed racketeering and conspiracy charges against Bigdoggie's owners a year later. Charges against four female escorts also were dropped.
A defense attorney argued the male clients were mere "hobbyists" who traded stories of their adventures with hired escorts, and their actions were constitutionally protected speech.
And in Minnesota, backpage.com has been under fire for its popular online ads of escort and "body rub" services that authorities say are ads for prostitution services.
David Brown, chief criminal deputy of Hennepin County, which includes Minneapolis, said Minnesota's laws are written broadly enough that authorities can prosecute those who use websites for prostitution. Still, he said even Minnesota authorities have limitations.
"We see backpage.com as a forum," Brown said. "What we do is go after the conduct."
That means authorities go after costumers and prostitutes who later engage in an exchange of money for sex after meeting online, he said. "With online sites, unless you have proof that the (owners) are openly promoting prostitution, there are limits," Brown said.
Officials with Backpage, owned by Village Voice Media, say the website is protected by the federal Communications Decency Act. Under the 1996 law, websites that host third-party content are not liable if third-party users post "indecent" content.
Confusion over the federal law, and the fact that state lawmakers feel powerless against it, could explain why states have avoided tackling online prostitution problems legislatively, said Cunningham, the Baylor University professor.
Instead, he said, states are allowing police and prosecutors to aggressively pursue targeted cases.
For example, in Kissimmee, Fla., authorities arrested around 70 people in May as part of an Internet prostitution sting. They used a decoy house to nab suspects on charges including entering a dwelling to commit prostitution.
Jason Scott, program director of the National District Attorneys Association based in Alexandria, Va., said although states' laws vary, authorities can go after websites in other ways. For example, if authorities can clearly identify that a site is promoting prostitution, they can go after the ISP address or use racketeering or corruption statutes to prosecute owners.
But Cunningham said authorities still face the challenge of trying to determine websites' role in alleged prostitution crimes.
"What some of these sites are doing are screening prostitutes and screening potential customers, much like what pimps have historically done," he said. "The question is: Can they be prosecuted like pimps?"
Follow Russell Contreras on Twitter at http://twitter.com/russcontreras.
Associated Press researcher Susan James in New York contributed to this report.