The governor of Montana, Greg Gianforte, signed a invoice on Wednesday to ban TikTok from working contained in the state, probably the most excessive prohibition of the app within the nation and one that can nearly definitely be challenged in court docket. The ban will take impact on Jan. 1.

“Today, Montana takes the most decisive action of any state to protect Montanans’ private data and sensitive personal information from being harvested by the Chinese Communist Party,” Mr. Gianforte, a Republican, stated in a news launch.

The Montana Legislature launched the invoice in February, resulting in months of debate. The proposal, which might have an effect on on a regular basis customers of the favored short-form video app, considerably escalated a nationwide rush to ban TikTok on authorities gadgets based mostly on issues in regards to the firm’s possession by the Chinese firm ByteDance. The battle over the invoice offered a glimpse of what the United States may encounter nationally if lawmakers or the White House try a nationwide ban of TikTok, which has been floated in latest months.

TikTok, which says it has 7,000 staff within the United States, has been combating again within the state for months. It has run advertisements that includes Montana small companies that use TikTok and given prewritten emails to customers so they might contact Mr. Gianforte about opposing the invoice.

The laws prohibits cellular app shops, like these run by Apple and Google, from providing TikTok inside the state. A commerce group funded by Apple and Google has stated in latest months that it’s not possible for the businesses to forestall entry to TikTok in a single state.

“Governor Gianforte has signed a bill that infringes on the First Amendment rights of the people of Montana by unlawfully banning TikTok, a platform that empowers hundreds of thousands of people across the state,” Brooke Oberwetter, a spokeswoman for TikTok, stated in an announcement on Wednesday. Montanans, she added, can preserve utilizing the app “as we continue working to defend the rights of our users inside and outside of Montana.”

Under the laws, TikTok may face fines if it continues working within the state, as may Apple and Google if they permit folks to obtain the app.

Apple and Google didn’t instantly return requests for remark.

The battle in Montana erupted throughout a interval of intense nationwide scrutiny on TikTok, which boasts greater than 150 million U.S. customers. Lawmakers and intelligence officers have said TikTok, due to its possession, may put delicate consumer information into the arms of the Chinese authorities, pointing to legal guidelines that enable Beijing to secretly demand information from Chinese firms and residents for intelligence gathering.

They have additionally expressed concern that the app, which is very widespread with youngsters and other people of their 20s, could possibly be used to unfold propaganda. Congress grilled Shou Chew, TikTok’s chief government, for roughly 5 hours at a March hearing that targeted largely on the app’s Chinese possession.

TikTok says it has by no means been requested to offer, nor has it offered, any U.S. consumer information to the Chinese authorities. The firm has proposed an in depth plan for working within the United States that it says ought to allay nationwide safety issues and fears of misinformation, however the plan has not but been accepted by the Biden administration, leaving TikTok and its future in limbo.

Free speech teams have been fast to reply to the Montana ban. The American Civil Liberties Union stated on Wednesday that the laws “flouts the First Amendment.”

“The government cannot impose a total ban on a communications platform like TikTok unless it is necessary to prevent extremely serious, immediate harm to national security,” the group stated in an announcement. “But there’s no public evidence of harm that would meet the high bar set by the U.S. and Montana Constitutions, and a total ban would not be the only option for addressing such harm if it did exist.”

The Montana invoice says the ban might be void if TikTok is acquired by, or offered to, an organization that isn’t included in a rustic “designated as a foreign adversary.”

David McCabe contributed reporting.