HELENA, Mont. (AP) — Five TikTok users filed a lawsuit to overturn a planned ban on the video sharing app in Montana.

They argued in a legal complaint filed late Wednesday in federal court in Missoula that the law is an unconstitutional violation of free speech rights.

They also say the state doesn’t have authority over matters of national security. Gov. Greg Gianforte signed the bill into law Wednesday and said it would protect Montana residents’ private data and personal information from being harvested by the Chinese government.

The ban is scheduled to take effect on Jan. 1, 2024.

“We expected a legal challenge and are fully prepared to defend the law,” said Emily Flower, spokeswoman for the Montana Department of Justice.

TikTok has argued that the law infringes on people’s First Amendment rights and is unlawful.

Some lawmakers, the FBI and officials at other agencies are concerned the video-sharing app, owned by ByteDance, could be used to allow the Chinese government to access information on U.S. citizens or push pro-Beijing misinformation that could influence the public. TikTok says none of this has ever happened.