A California judge on Wednesday dismissed criminal pimping charges against the chief executive and controlling shareholders of Backpage.com, ruling that a federal immunity shield for tech companies protected them from prosecution.

Backpage, the second-largest U.S. online classified ad service after Craigslist, has faced scrutiny from the U.S. Senate as well as civil lawsuits over allegations that the site facilitates sex trafficking, especially of children.

California Attorney General Kamala Harris last month brought criminal charges against Carl Ferrer, the Backpage CEO, along with shareholders Michael Lacey and James Larkin. However, the defendants argued that the ads on Backpage were posted by third parties and that the state offered no evidence that the defendants knew ads placed by escort services were solicitations for sex.

Under the federal Communications Decency Act, the defendants argued that they could not be prosecuted for content posted by third parties.

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In a tentative ruling on Wednesday, Sacramento County Superior Court Judge Michael Bowman agreed, saying Congress passed the Communications Decency Act to protect free speech online.

“Congress has spoken on this matter and it is for Congress, not this Court, to revisit,” Bowman wrote.

California judges often issue tentative rulings, which are then finalized after a hearing with few major changes.

A representative for the attorney general’s office could not immediately be reached for comment.