One day after Montana Governor signed the first statewide ban on TikTok into law, the measure is already facing a legal challenge. Five TikTok creators are suing in an effort to block the ban from taking effect.

In court filings, lawyers representing the TikTok creators say the ban is unconstitutional and that it violates their First Amendment rights. They also take issue with Montana’s supposed national security justification for the ban. 

“Montana has no authority to enact laws advancing what it believes should be the United States’ foreign policy or its national security interests, nor may Montana ban an entire forum for communication based on its perceptions that some speech shared through that forum, though protected by the First Amendment, is dangerous,” the suit states. “Montana can no more ban its residents from viewing or posting to TikTok than it could ban the Wall Street Journal because of who owns it or the ideas it publishes.”

In an interview on Fox News, Montana’s Attorney General, Austin Knudsen, said that legal challenges to the ban were expected. “There are some important issues here that I do think we probably need the federal courts to step in and answer for us here,” he said. “And that was part of our calculus in bringing this.”

The lawsuit is among the first legal challenges to the law, and will likely be closely watched as federal officials consider a nationwide ban on the app. Right now, the Montana ban is set to take effect January 1, 2024, though lawsuits challenging it could delay that timeline. TikTok itself hasn’t commented on whether it’s planning to bring its own litigation in Montana, but said in a statement following the bill’s signing that it planned “to defend the rights of our users inside and outside of Montana.”