The photograph captures two boys, about 6 or 7 years old, cavorting naked on a beach. One of the boys looks coyly over his shoulder. The other has an erection.

Child pornography or art?

Definitely art, according to a growing number of websites charging up to $40 a month for subscribers to gain access to images of naked children as young as 4 years old.

"Only the youngest and sweetest virgin boys!" reads the introduction to Nude Boys World (See editor's note below), which contains photos and movies of boys in the buff posing in shower stalls and unmade beds.

Likewise, Sunny Lolitas, which shows naked pre-pubescent girls playing with stuffed animals or stretched out pin-up style against hot red backgrounds, advertises its models as "only cutest and (sic) the youngest!"

Experts say the sites – which are easily found using Internet search engines – fall into a murky category known as "child erotica," which includes images of naked children that don't meet the strict legal definitions of child pornography. U.S. law defines kiddie porn as depictions of minors engaged in sexually explicit conduct, such as intercourse and masturbation, or that show "lascivious exhibition of the genitals or pubic area."

"These sites thinly skirt the line between legal and illegal," said Ruben Rodriguez, the director of the Exploited Child Unit of the National Center for Missing and Exploited Children, which works with the FBI to investigate Internet child porn. "It's very frustrating for us. They're making money exploiting children and there's nothing we can do to shut them down."

Most of the child erotica sites link to the same legal boilerplate, which characterizes the sites' content as art and manifests a "vehement" opposition to child pornography.

The disclaimers published by Little-Boyz – which boasts of being "the biggest nude boys site" with 20,000 photos and hundreds of movies – is typical of other child erotica pages:

"Every photo honors the purity and innocence of youth and contains no sexually explicit conduct in accordance with United States Law!" asserts the site. "In the time honored tradition and within the laws of the United States of America and most states and municipalities, the visual depiction and appreciation of the male form, including the pubescent male form, has been and is legal. Little Boyz supports the laws of the United States of America and gladly and willingly conforms to these laws ... Little Boyz, in accordance with the Constitution, believes that the right to view and appreciate nude images of minors in an artistic and aesthetic manner is guaranteed."

For good measure, many of the sites provide a direct link to the U.S. code defining child pornography.

But even if the sites don't show minors engaged in sexually explicit conduct, they could be charged for lascivious intent, said Ken Lanning, a retired FBI agent who spent 30 years researching crimes against children and now serves as an expert witness in court cases.

However, proving lascivious intent in court is extremely difficult. The prosecutor would have to demonstrate that the producer of the material intended to elicit a sexual response with the images or that the subscriber viewed the images for sexual arousal.

Unless the images are in a folder called something like, "hot little kids I'd like to have sex with," it would be hard for prosecutors to argue that the subscriber had lewd interest in the material.

The material could also prove damaging in cases where a defendant has previous convictions for child pornography or molestation, he added. In the 1995 landmark case, U.S. v. Stephen Knox, a known pedophile was sentenced to jail for possessing tapes of young girls in leotards whose dancing the court qualified as "lascivious."

But such convictions are few and far between, said Lanning, who predicted that child erotica sites will proliferate as the government continues to break up hard-core child pornography rings.

"The reality is, there's so much hard-core stuff out there that prosecutors don't want to get bogged down with these kinds of sites," he said. "It's a fuzzy area of the law."

The line between art and illegal porn has perplexed law enforcement authorities for decades. Take the controversial work of Jock Sturges, whose photographs depict naked adolescent girls. Despite an FBI raid, protests by angry mobs and a grand jury investigation, his coffee table art books continue to sell.

But a closer look at the child erotica sites suggest that their content isn't aimed at art connoisseurs. First, there are the site names: Lolitas For Sale, Boy Erection, and Pedo Art (pedophile art), among others.

Second, there's the content: Some of the images available on the preview tour seem blatantly suggestive, such as a photograph of a pair of young boys in a shower, with one boy directing the water nozzle at the other's buttocks.

Then there are the rules. One site prohibited U.S. law enforcement agents from joining and forbade members from holding the site owners responsible for breaking laws.

Most of the sites are registered in foreign countries. But they are written in English and billed through American bill processors. Two of the billing companies that process charges for the child erotica sites, iHasp and BillCards, offer anonymous debit card services to webmasters, allowing them to receive payments without being directly linked to such seamy-sounding sites as Lusty-Lolitas.com.

Perhaps the most damning evidence can be found in the introduction of a website called Boys Mania, where the Russian photographer explains how he recruits his models:

"I always have a possibility to find secluded places where kids are trying to hide from their parents and teachers.... Sometimes I manage to talk to them and invite them to my house, show them pictures, videos and other stuff with lots of naked boys and girls. When being with them I try to undress myself first and then offer them to do the same. I like their smooth skin, their fascinated looks, the way they play together and with themselves. I feel excited when they are turning on."

E-mails to the webmasters of this and several other sites went unanswered.

The child erotica sites are often a gateway to illegal material, said Cate Donoghue, the director of Online Guardians, a group that monitors the Internet for pedophiles and indecent images of children.

Subscribers may find that the site contains hard-core child pornography or that their e-mail address has been sold to mailing lists that bombard them with offers to join illegal sites, she said.

One spam her organization detected at the end of April, for example, directed recipients to a page containing graphic images of sexual activity involving toddlers. The site, which authorities have tried to close for more than a year, keeps hopping from one IP address to another. Another site featuring hard-core photos of "tiny little girls" brags: "Our server was closed 21 times, but we have risen from the ashes again."

For Donoghue and other cyber-vigilantes, keeping up tabs on cyber smut is a full-time job.

"Sites that exploit children persist because there are enough perverts out there willing to pay big bucks to see them," said Donoghue. "We have yet to find a way to keep them offline."

(Editor's note: An unwritten but conventional Wired News policy is to provide links to websites covered in our stories. However, we have made an exception in this case. Because of the nature of the content of these websites, we have serious reservations about directing our readers to the images that can be found there.)

Behind the Kid 'Erotica' Scenes

Girl Model Sites Crossing Line?

Round Two on 'Morphed' Child Porn

Porn Hunters Unwelcome in Canada?

Discover more Net Culture

Give Yourself Some Business News