• by Wendy Davis , Staff Writer @wendyndavis, June 18, 2012

Two years ago Craigslist decided to shutter its controversial adult services listings -- which often carried thinly veiled prostitution ads.

Craigslist wasn't legally required to do so. In fact, the company had prevailed in litigation over the ads, with more than one court ruling that the federal Communications Decency Act immunmized Craigslist from liability. That law says that Web sites generally aren't liable for posts by users (except when they post material that infringes intellectual property).

Nonetheless, Craigslist closed the controversial listings. At the time, it told Congress that the ads would almost certainly migrate to other sites.

That seems to be exactly what happened. In the last two years, Backpage.com has become infamous for hosting prostitution ads -- including, in some cases, ads that appear to feature teens. Village Voice Media's Backpage recently was sued by one teen sex trafficking victim, who said the company aided and abetted prostitution by allowing sex ads on Backpage.com. That case was dismissed last year by a federal magistrate judge in Missouri, who ruled that the company was protected by the Communications Decency Act.

Attorneys general and others have continued to pressure Backpage to stop allowing users to post prostitution ads, but such ads continue to appear on the site. Backpage's general counsel Liz McDougall says the company "works cooperatively with law enforcement to identify, arrest and prosecute human traffickers."

Those efforts weren't enough for lawmakers in Washington, who recently passed a measure aimed at ending online ads related to sex trafficking of minors. The law (SB 6251) makes it a felony for Web site operators to allow users to post ads for "commercial sexual acts," when those ads contain images of minors.

Earlier this month, Backpage.com obtained a temporary injunction prohibiting law enforcement officials from prosecuting anyone under the new law. Backpage argues that the measure runs counter to the federal Communications Decency Act.

The company also says the law marks an illegal attempt by the state of Washington to impose obligations on companies that operate on a national level. In general, the constitution prohibits states from regulating interstate commerce -- which is why some state judges have invalidated state laws requiring online retailers to collect sales tax from residents.

The online listings site contends that Washington's new law potentially affects every site that accepts user-generated content by imposing new policing duties on Web sites. The Washington statute says Web site operators are liable if they allow users to post explicit or "implicit" prostitution ads, unless the site operators obtain drivers' licenses or other identification of individuals depicted. "These obligations would bring the practice of hosting third-party content to a grinding halt," Backpage argues in its court papers.

Last week, the Internet Archive said it, too, intends to fight the Washington law in court. The group -- which maintains records of old Web pages, including those of Backpage.com -- filed papers seeking to intervene in the case in order to challenge the law.

"Because of its expansive language," the group argues, "the law could be applied not only to online classified ad services like Backpage.com but also to any web site that provides access to third-party content, including user comments, reviews, chats, and discussion forums, and to social networking sites, search engines, Internet service providers, and more."

The organization adds: "A law that takes such an overbroad approach is of serious concern to the Internet Archive, which aims to serve as a library for the Internet, and accordingly, houses more than 150 billion web pages archived since 1996."

The next hearing in the case will take place in July.