A lawyer told the Washington Supreme Court on Tuesday that a lawsuit filed by three young girls who were sold as prostitutes on a website should be thrown out because the website didn't write the ads, so it's not liable.

But the victims' lawyer said the website, Backpage, doesn't have immunity under the federal Communications Decency Act because the website markets itself as a place to sell "escort services" and provides pimps with instructions on how to write an ad that works, making them a participant in the largest human-trafficking website in the U.S.

The justices plan to rule on the case at a later date.

Before the hearing several dozen people stood in the rain on the court steps with signs that read: "People's bodies are not commodities," ''End Child Slavery" and "Stop Buying Our Girls."

"No one has the right to sell a kid for sex," said Jo Lembo, with Shared Hope International. "That's why we're here. Someone has to speak up for them. They're kids."

A similar case was filed last week in federal court in Boston, but a previous case in Missouri was dismissed, said Yiota Souras, a lawyer with the National Center for Missing & Exploited Children. "The Washington state case has gone further than any previous case," she said.