A popular cannabis community website, Weedmaps , which features ads and other listings related to marijuana businesses across the Golden State, has invoked a federal law as a way to stave off the ire of California’s cannabis authorities.

Last month, the Bureau of Cannabis Control (BCC), the state entity that oversees California’s newly legal recreational marijuana market, sent a letter to Weedmaps last month, saying that because the website allows ads for companies that are not officially licensed by the state, it is in violation of state law. (The spat was first reported by The Sacramento Bee.)

On Monday, Weedmaps executives responded with their own letter, saying that Section 230 of the Communications Decency Act, a federal law that removes liability of a website for the actions of its users, acts as its shield. Digital rights groups including the Electronic Frontier Foundation have argued that Section 230 is what protects the Web as a whole—publishers don’t have to worry about being sued if one of their users is accused of violating the law.

A revision of the law is currently being proposed with the Allow States and Victims to Fight Online Sex Trafficking Act, which, according to the EFF, would “punch a hole” in Section 230. The new bill is aimed squarely at Backpage, a notorious website that continues to allow prostitution advertisements.

Weedmaps CEO Doug Francis and President Chris Beals wrote to the BCC that they believe their company is shielded by Section 230.

“We note at the outset that Weedmaps is a technology company and an interactive computer service which is subject to certain federally preemptive protections under Section 230 of the Communications Decency Act and is also not a Licensee subject to the Bureau’s purview pursuant to [Medicinal and Adult-Use Cannabis Regulation and Safety Act] or State regulations,” they wrote. “Nonetheless, as a technology company that has serviced this industry for a decade and as a company which employs almost 300 California residents, we wish to work together as a partner with California to find a solution to the concerns you raise.”

Jeffrey Kosseff, a law professor at the United States Naval Academy and an expert on Section 230, told Ars that he believes Weedmaps is in the right.

“My initial impression is that, under even a very limited reading of Section 230, it is difficult to see how Weedmaps could be held liable for these ads,” he emailed. “There is not an exception to 230 for state marijuana licensing, as there is for federal criminal law and intellectual property. Assuming that the ads are created entirely by the unlicensed retailers, then that is classic third-party content that is covered by Section 230.”

Similarly, Eric Goldman, a law professor at Santa Clara University, largely concurred.

"Weedmaps should qualify for Section 230 protection, but the implications of that are perhaps more ambiguous than their flat declarations indicate," he emailed Ars.

Still, it’s not clear what the BCC will do next.

A spokesman for the BCC, Alex Traverso, emailed Ars: “At this time, we are reviewing the letter and determining the appropriate next steps.”