(CNN) — TikTok filed a lawsuit on Tuesday to block a US law that would lead to a national ban on the popular app. The lawsuit comes after the company issued legal threats after US President Joe Biden signed the law into law last month.

The court challenge represents the start of a historic legal battle that will determine whether U.S. security concerns over TikTok's ties to China can block the First Amendment rights of TikTok's 170 million U.S. users.

The stakes in this case are important for TikTok. If TikTok fails, TikTok could be banned from US app stores unless its Chinese parent, Byte Dance, sells the app to a non-Chinese company by mid-January 2025.

within it Petition In a filing Tuesday in the United States Court of Appeals for the District of Columbia Circuit, TikTok and Python allege the law is unconstitutional because it stifles Americans' speech and prevents them from accessing legal information.

The petition claims that the US government has “unprecedentedly dissociated and expressly prohibited” the use of short-form video in an “unconstitutional exercise” of congressional authority.

“For the first time in history, Congress has passed a law that permanently bans a specific speech platform nationwide and prohibits participation in an online community of more than 1 billion people worldwide.”

The White House referred questions about TikTok's legal challenge to the Justice Department, which did not respond to a request for comment.

The lawsuit comes after years of U.S. allegations that TikTok's ties to China could expose Americans' private information to the Chinese government.

Discussion of data sharing

TikTok has vehemently denied access to US user data to Chinese government officials and says it has taken steps to protect that information by hosting the data on servers owned by US tech giant Oracle.

Those actions are part of a 90-page draft agreement before a government panel called the Commission on Foreign Investment in America, a multi-agency body that has been reviewing TikTok's operations in the United States since 2019. The same draft agreement also includes the US government's ability to shut down TikTok if the app or ByteDance “breach certain obligations under the agreement.”

But those assurances have not allayed the concerns of U.S. officials, including fears that China could use TikTok data to identify intelligence targets, spread propaganda or engage in other forms of covert influence.

To date, the U.S. government has not publicly presented any concrete evidence proving the Chinese government's access to TikTok data. US lawmakers received classified briefings from national security officials behind closed doors, but did not declassify any material from those meetings.

Reactions to the clarifications were mixed: One House Republican said there was “no specific information … that's strong evidence” and one House Democrat said the decision was down to how to curb China's “malign influence.”

But Sen. Mark Warner, Democrat of Virginia, a sponsor of the TikTok legislation, said in comments on the Senate floor in April that he had summarized important information about the danger posed by TikTok.

“Many Americans, especially young people, are rightly skeptical of the law regulating TikTok,” Warner said in his comments. “In the end, they didn't see what Congress saw. They were not present at a secret briefing held by Congress that explored some of the threats posed by foreign control of TikTok.

In March, those fears culminated in legislation that gave TikTok about six months to sell or face a ban in the US. Passed by the House, an updated version of the bill was fast-tracked and stalled in the Senate before being attached to a major foreign aid package that would benefit Israel and Ukraine.

US lawmakers described the law in question as a mandatory exemption from TikTok, not an outright ban on the app. However, TikTok has insisted that a ban is the only possible outcome if the law is upheld.

“The 'qualified exemption' required by law to allow TikTok to continue operating in the United States is simply impossible,” the petition said Tuesday, “not commercially or technically or legally.”

Implications of the First Amendment

TikTok and ByteDance call the national security concerns that are at the heart of the TikTok Act, adding in the petition that the bill's quick passage reflects “speculation and speculation” by its authors in Congress. Evidence, “the First Amendment required,” to plead his case.

First Amendment experts say TikTok's claims have some merit. For example, the Supreme Court held that the U.S. government could not prohibit the U.S. government from receiving foreign propaganda if they wanted to. To underline this point, the law is called Berman correction It also prohibits U.S. presidents from blocking the free flow of media from foreign countries deemed hostile to the United States.

“National security claims should not trump the First Amendment,” said Evelyn Duke, an assistant law professor at Stanford University who studies the regulation of online sites. “Otherwise, the Constitution will have no real value. At the very least, the government should be forced to provide evidence for its claims. There is precedent for (the Supreme Court) ignoring these principles, particularly in the context of counter-terrorism and foreign speech.

TikTok won some early court victories last year as several US states tried to regulate the use, foreshadowing a coming battle over online speech. In Montana, the only state to pass its own TikTok ban affecting personal devices, a federal judge temporarily blocked the law, saying the state law was unconstitutional and “cut off victims' (users') First Amendment rights and the income many depend on.”

The bipartisan nature of the law Biden signed will convince courts of the seriousness of national security concerns surrounding TikTok, said Gautham Hance, co-director of Cornell University's First Amendment Clinic. Still, Hance said, “without a public debate about what the stakes are…it is difficult to determine why courts should review an unprecedented statute.”

In addition to potentially infringing on the free speech rights of US TikTok users, the federal law challenging TikTok also involves the constitutional rights of Apple and Google, which would be barred from carrying TikTok on its app stores if the ban goes into effect.

“This raises concerns about unconstitutional government intrusion into decisions about what content these sites should contain,” Jennifer Huddleston, a researcher at the libertarian Cato Institute, wrote in an op-ed last month. “Also, it could set a dangerous precedent of government intervention in the online space that many would condemn in the offline space.”

However, the US government and more than half of the states have restricted TikTok to government devices, reflecting the need for governments to manage their own property. Internationally, TikTok has been banned on government devices in Canada, the United Kingdom and the European Commission. This app is completely banned in India from 2020 onwards.

Some US officials have been trying to ban TikTok in the US since 2020, when former President Donald Trump moved to ban the app through an executive order. (Trump has since reversed his position, saying a ban on TikTok would only help Meta, which Trump blames for his 2020 election loss.)

The outcome of the TikTok case could have major implications for how the U.S. government regulates technology and other foreign speech, Doug said.

“It's very important to think about this not just in terms of TikTok, but in terms of all foreign platforms in the future,” Doug said. “In a globalized world, this issue will come up again and again. Giving the government the power to ban a site based on concerns about potential future harm, rather than real, clear and present dangers, would be more worrisome.