Attorney General Sam Olens and 45 other attorneys general today called for information about how Backpage.com presumably attempts to remove advertising for sex trafficking, especially ads that could involve minors.

In a letter to the online classified site’s lawyers, the attorneys general say that Backpage.com claims it has strict policies to prevent illegal activity. Yet, there are more than 50 cases, in 22 states over three years, involving the trafficking or attempted trafficking of minors through Backpage.com. “These are only the stories that made it into the news; many more instances likely exist,” the attorneys general wrote. They also reminded Backpage.com of a 2010 request from nearly two dozen attorneys general asking that the adult services site be taken down.

“Child sex trafficking has become an epidemic for Georgia and the entire Nation,” said Attorney Sam Olens. “While I am proud that the State of Georgia recently enacted a new law that serves as a national model for combating sex trafficking, our work is not over. We must continue to look for ways to protect the vulnerable from abuse by traffickers. Backpage.com should not be allowed to provide a tool to bad actors which facilitates this form of modern day slavery.”

In many cases involving human trafficking on Backpage.com, law enforcement finds that minors are coerced. Prosecutors in Benton County, Wash., are handling a case in which teen girls say they were threatened and extorted by two adults who marketed them on Backpage.com. One of the adults rented a hotel room and forced the girls to have sex with men who answered the online ads. Backpage.com charges $1 and up for such ads.

While Backpage.com has ramped up its effort to screen some ads for minors, the attorneys general involved in today’s letter believe that “Backpage.com sets a minimal bar for content review in an effort to temper public condemnation, while ensuring that the revenue spigot provided by prostitution advertising remains intact.”

Backpage.com, owned by Village Voice Media, LLC, is the top provider of “adult services” advertisements. Industry analysts suggest that Village Voice’s stake in adult services advertisements is worth about $22.7 million in annual revenue.

The letter is attached.