• by Wendy Davis , Staff Writer @wendyndavis, December 7, 2012

Washington Attorney General Robert McKenna this week promised not to prosecute Backpage.com for running illegal prostitution ads.

The move marks an end to litigation about a new Washington law that 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. That law (SB 6251) was supposed to take effect in June, but Backpage obtained a preliminary order prohibiting enforcement. This week, Backpage and the state authorities signed an agreement making that order permanent.

When Backpage sued to block the law, the listings site argued that the measure imposed new policing duties that would ultimately affect all sites that accept user-generated content. The Washington statute imposes liability if Web site operators allow users to post prostitution ads -- even ones that only imply prostitution -- unless the sites obtain drivers' licenses or other identification of anyone depicted in the ads.

Those requirements "would bring the practice of hosting third-party content to a grinding halt," Backpage said in its papers.

The listings site argued that the Washington law conflicted with the Communications Decency Act, which immunizes sites from liability when users upload illegal material. That immunity enables Web companies to offer users interactive platforms without monitoring their posts. Backpage also argued that the law is written so broadly that it unconstitutionally restricts legitimate speech.

The Internet Archive, which maintains an online library of old Web pages (including those of Backpage.com), joined in Backpage.com's challenge to the law. In July, U.S. District Court Judge Ricardo Martinez in Seattle ruled that Backpage and the Internet Archive were likely to prevail.

The settlement agreement, awaiting approval by Martinez, provides that the state will pay $200,000 to Backpage.com and the Internet Archive, to reimburse them for their legal bills.

Even though McKenna won't prosecute Backpage, the company is certain to face continued pressure on this issue. For one thing, the state of Tennessee passed a law that's nearly identical to the one in Washington. Backpage currently is challenging that law as well.

Also, three teen sex trafficking victims recently filed a civil lawsuit against the listings site, alleging that they were abused as a result of ads on the site. That case is pending in federal court in Tacoma, Wash.

The listings site defeated a similar lawsuit last year, after arguing that it was immune from liability under the Communications Decency Act.

For its part, Backpage has said in the past that the company "works cooperatively with law enforcement to identify, arrest and prosecute human traffickers."

Craigslist also faced litigation over prostitution ads. The company prevailed, but nonetheless decided in 2010 to shutter its adult listings. At the time, Craigslist executives predicted -- correctly, as it turns out -- that the ads would migrate to other sites.