Websites told: Label smut or face prison

Operators of commercial websites with sexually explicit content would have to post warning labels on each offending page or face imprisonment under a new proposal in the US Senate.

Caving in to earlier demands from the US Department of Justice, the 24-page proposed law focuses on a medley of new penalties related to child pornography and other sexual content on the internet. For instance, ISPs that fail to report to authorities any sightings of child pornography on their networks would have to cough up fines that are triple those written into current law: $150,000 for the first violation and $300,000 thereafter.

Senator Jon Kyl, an Arizona Republican, who joined eight members of his party in introducing the bill on Tuesday, said: "The increase in internet use has given sexual predators new ways to prey on children. This bill, among other things, is intended to shut down these opportunities, and severely punish the degraded individuals who are involved in the sexual exploitation of our youth."

The bill, which is called the Stop Adults' Facilitation of the Exploitation of Youth Act, or Internet Safety Act, beefs up the Justice Department's suggested penalties for negligent web labellers. It would impose up to 5 years in prison on any commercial site operator who fails to place "clearly identifiable marks or notices" prescribed by the federal government in either the site's code or on the pages themselves, according to a copy of the bill seen by silicon.com sister site CNET News.com.

The bill would also create a new crime out of "using misleading domain names to direct children to harmful material on the internet". Conviction would carry a prison sentence of up to 20 years. A similar sentence would apply to anyone who knowingly embeds words or images in the source code of their sites with the intention of deceiving minors into viewing "harmful" content.

The US attorney general Alberto Gonzales originally called for the new laws while speaking at an event at the National Center for Missing and Exploited Children in April. He said a mandatory rating system is necessary to "prevent people from inadvertently stumbling across pornographic images on the internet".

The proposal drew criticism from civil liberties advocates, who said it presents enough ambiguities to prompt self-censorship of web content.

David Greene, director of a free-speech advocacy group called The First Amendment Project, said: "Whether artistic works or political commentary or any type of images that may arguably come close to this category, people may not publish them for fear of being sent to jail."

It's equally unclear how to draw the line between "commercial" websites, covered by the regulations, and "non-commercial" sites, which appear to be exempt, the bill's critics said.

Greene said: "They may sell T-shirts or do things that are unrelated to the image or the content that is labelled. When their commercial transaction doesn't relate to the image, to the sexual content, there's a great danger in these laws."

The Internet Safety Act pulls its definition of sexually explicit material from existing federal law. It covers sexual intercourse of all types: bestiality, masturbation, sadistic or masochistic abuse, or lascivious exhibition of the genitals or pubic area of any person.

In practice, however, courts have interpreted those definitions quite broadly - in one case courts ruled that the "lascivious exhibition" of the pubic area could include images of clothed people wearing bikini bathing suits, leotards and underwear.

The Senate proposal grants just one reprieve: sexual depictions that constitute a "small and insignificant part" of a large website do not have to be labelled.

CNET News.com's Declan McCullagh contributed to this report

Anne Broache writes for CNET News.com