“Until our investigation showed Backpage was actively facilitating sex trafficking, the company had repeatedly used the federal law that protects online platforms to escape accountability for the disgusting crimes it aided,” said McCaskill, a former prosecutor. “But even as we’ve helped deny Backpage its legal shield in these cases, we need a broader effort to stop the next Backpage, before it starts. And that’s what this bipartisan bill is all about—better protecting Missouri’s families from sex trafficking by making clear to any company considering going into business with sexual predators, that the law won’t protect them from responsibility.”

Backpage has stated that it monitors and removes thousands of ads and helps law enforcement track down pimps and rescue trafficked children. Some say that targeting Backpage will only displace the sex ads to other websites, that Backpage is more responsive to police than other sites, and that closing Backpage’s adult ads wouldn’t address the underlying problem of adult male demand for underage commercial sex.

In April, Rep. Ann Wagner (R-Mo.) introduced a slightly broader bill in the House which now has 101 co-sponsors. In addition to amending the Communications Decency Act, it also seeks to amend the federal criminal code to say that any website provider who publishes information from anyone, “with reckless disregard that the information … is in furtherance of” sex trafficking of a person under 18 “shall be fined … or imprisoned not more than 20 years, or both.”

Consumer Watchdog, an advocacy group that recently published a report on the Internet groups who oppose changing the decency act, issued a letter last month to the chairmen and ranking Democrats of the committees considering Wagner’s bill, calling on them to schedule hearings immediately. “Internet freedom,” the group wrote, “must not come at the expense of children who are sex trafficked.”