Attorneys for Backpage.com argued that the law will force sex trafficking further underground, where it will be far more difficult to police, and said that the law infringes on free speech.
On Friday, U.S. District Court Judge Ricardo Martinez granted the injunction. Bauer, the attorney for the three girls, responded that it was "ridiculous" to call this an issue of freedom of speech.
"How about, basic freedom for kids? How about freedom to live life happy and joyous? Freedom of life, liberty and the pursuit of happiness are constitutional rights. And children have them. These freedoms are more import than corporate freedom-of-speech rights," he said in an interview with ABC News.
Bauer also argued that the nature of Backpage's listings create a "volume business." He said the girls were sent to clients for sex up to 20 times per day. He said he doesn't believe that the company's "triple-tier prevention system" makes a difference.
"Their policing is completely ineffective," he said. "I don't think they're serious about it. If they were, then they wouldn't be fighting tooth and nail against the law."
McDougall said that closing down Backpage.com will not prevent the exploitation of children. She said the solution lies in stopping the demand.
"What I find frustrating with this lawsuit is that we finally have a focus on child trafficking in the U.S., and we've ignored that, until five or six years ago," she said. "[Now] all of the attention is being focused on Backpage. If you shut down Backpage, it's not going to solve the problem.
"The endgame is that the same activity will continue to occur, but it will just move into the deeper part of the web -- or offshore," she said. "When it goes offshore, they're not in the jurisdiction of law enforcement. There's nothing we can do."