The U.S. Senate voted Tuesday to approve a bill that would ban TikTok nationwide unless Chinese parent company ByteDance sells its stake in the popular app.

The development will likely result in a court battle between the U.S. and TikTok, which argues that the legislation violates the First Amendment — and if TikTok loses that fight, there’s a real chance it could be shut off for Americans.

The bill now moves to the desk of President Biden, a supporter of the TikTok divest-or-ban measure who has said he will sign it into law. U.S. lawmakers have expressed deep concern about TikTok’s Chinese ownership, suggesting that the Chinese communist regime could use the app to spy on Americans or use it to promulgate pro-China propaganda.

The Senate approval of the TikTok ban bill was tied to a $95 billion package of foreign aid to Ukraine, Israel and Taiwan.

The Senate, by a 79-18 vote, OK’d the bundled legislation after the House passed the resolutions Saturday and sent them on an expedited basis to the Senate for approval on an up-or-down vote.

TikTok will file a legal challenge once the bill is signed into law, Michael Beckerman, TikTok’s head of public policy for the Americas, wrote in a memo to company staff over the weekend.

The legislation is a “clear violation” of the First Amendment, the exec wrote: “This is the beginning, not the end of this long process.” Beckerman also criticized the TikTok divest-or-ban measure as “an unprecedented deal worked out between the Republican Speaker [Mike Johnson] and President Biden.”

Ahead of the vote, Sen. Mark Warner (D-Va.), chair of the Senate Intelligence Committee, delivered comments on the Senate floor Tuesday afternoon about the national security threats posed by ByteDance’s ownership of TikTok.

Passage of the bill “goes a long way towards safeguarding our democratic systems from covert foreign influence,” he said, saying that Chinese companies like ByteDance “don’t owe their obligation to their customers, or their shareholders, but they owe it to the PRC [People’s Republic of China] government.”

“This is not an effort to take your voice away…  I would emphasize this is not a ban of the service you appreciate,” Warner said, addressing TikTok users. Regular Americans aren’t privy to classified briefings members of Congress have received about TikTok from intelligence services and the risks it poses as an entity “operating at the direction of a foreign adversary,” Warner said.

“We hope that TikTok will continue under new ownership — American or otherwise. It could be bought by a group from Britain, Canada, Brazil, France. It just needs to no longer be controlled by an adversary that is defined as an adversary in U.S. law.”

Sen. Maria Cantwell (D-Wash.), chair of the Senate’s Commerce, Science and Transportation Committee, suggested TikTok and ByteDance are “weaponizing” data and AI to spy on American citizens, the military and government personnel, including journalists covering the company. (In 2022, ByteDance said it fired four employees for “misconduct” after the company found they accessed TikTok data on several users, including two reporters.)

Sen. Ed Markey (D-Mass.) spoke out against the TikTok ban bill before the final vote, saying the more pressing “clear and present danger” is the harm kids face from social media apps more broadly, including from U.S.-based companies.

“I don’t deny that TikTok poses some national security risks,” Markey said. “TikTok has its problems. No. 1, TikTok poses a serious risk to the privacy and mental health of our young people.” But he said the bill likely would result in “widespread censorship,” and he suggested that the bill’s supporters object to liberal political viewpoints popular on TikTok.

“Instead of suppressing speech on a single application, we could be addressing the root of the mental health crisis by targeting Big Tech’s pernicious, privacy-invasion business model of teenagers and children in our country,” Markey said.

TikTok has said the bill, if it becomes law, would infringe the free-speech rights of its 170 million U.S. users and “devastate” the estimated 7 million American businesses on the platform. It claims TikTok contributes $24 billion to the U.S. economy annually.

The TikTok divest-or-ban legislation has been opposed by the ACLU and other advocacy groups.

“This is still nothing more than an unconstitutional ban in disguise,” Jenna Leventoff, senior policy counsel at the ACLU, said in a statement Tuesday prior to the Senate vote. “Banning a social media platform that hundreds of millions of Americans use to express themselves would have devastating consequences for all of our First Amendment rights, and will almost certainly be struck down in court.”

Because of its Chinese ties, TikTok has been a political football in the United States for years, as well as in other countries (including India, where it’s been banned since June 2020).

TikTok has prevailed in challenging other laws in the U.S. seeking to ban the app. Last December, a federal judge blocked Montana’s first-of-its-kind statewide ban of TikTok, ruling that the law likely violated the First Amendment.

An attempt by the Trump administration to force ByteDance to sell TikTok or face a ban also was found unconstitutional by federal courts on First Amendment grounds.

Under the “Protecting Americans From Foreign Adversary Controlled Applications Act” bill, Apple and Google’s app stores and web hosting services in the U.S. would be barred from hosting any “foreign adversary controlled application.”

Specifically, it would prohibit distribution of TikTok unless ByteDance divests its ownership in the app within nine months of becoming law, with an additional 90-day extension possible at the president’s discretion if “a path to executing a qualified divestiture has been identified.”

Johnson, the House speaker, incorporated the TikTok ban (revised with the extended divestiture timeline) into the emergency supplemental appropriations bill in a bid to win Republican support for the package of foreign aid.

Backers of the TikTok bill argue that it doesn’t restrict free speech, saying it only requires apps to be owned by a company that isn’t subject to the control of an adversarial foreign government.

As a precedent, the legislation’s proponents point to the 2020 sale of the dating app Grindr by Chinese gaming company Beijing Kunlun Tech Co. to a group of U.S.-based investors, a transaction forced by the U.S. government over concerns about the privacy of the app’s users.

Per the text of the bill, legal challenges to the “Protecting Americans From Foreign Adversary Controlled Applications Act” may be filed only in the U.S. Court of Appeals for the District of Columbia Circuit.

If TikTok is unsuccessful in getting the divest-or-ban law overturned, it is unlikely that ByteDance would sell its ownership stake — and that the app would effectively become outlawed in the U.S.

Chinese officials have said the government would “firmly oppose” any forced sale of TikTok, which would represent a technology export and be subject to the government’s approval.

“You’re not going to be able to force ByteDance to divest,” James Lewis, SVP at the Center for Strategic and International Studies, told the New York Times last month.