TikTok Inc has filed a lawsuit against Montana for banning the use of their app, becoming the first state to do so. TikTok argues that the ban, set to start on 1 January, violates the company's and its users' First Amendment rights. It also claims that the ban goes against federal law by encroaching upon matters under exclusive federal jurisdiction and violating the Commerce Clause of the US Constitution, which limits states from passing legislation that excessively burdens interstate and foreign commerce.

TikTok, owned by China's ByteDance, has been facing increasing pressure from US lawmakers and state officials who are concerned about potential Chinese government interference on the platform. Under the new law, Montana has the authority to impose fines of$10,000 for each TikTok violation, with additional daily fines if the ban is violated. However, it remains uncertain how the ban will be enforced.

In the past, former President Donald Trump attempted to ban TikTok and WeChat, another Chinese-owned app, but court decisions prevented the bans from taking effect. Senate Intelligence Committee Chair Mark Warner believes that TikTok's lawsuit makes it even more crucial for Congress to pass legislation granting the president new powers to ban or impose restrictions on foreign-owned apps like TikTok.

TikTok is estimated to have hundreds of thousands of active users in Montana and stated that it has not shared and would not share US user data with the Chinese government, emphasising its efforts to protect user privacy and security.

Five TikTok users in Montana have also filed a lawsuit aimed at blocking the state's ban. The lawsuit names Montana Attorney General Austin Knudsen responsible for enforcing the law. The Attorney General's office has not yet commented on the matter.