TikTok now risks becoming a high-profile casualty of the cold-war sequel developing between China and the United States.
It's one of the world's most popular social media platforms, wildly popular with younger people. And, within a year, it could be banned in the U.S.
At issue is a provision tacked into a sprawling piece of legislation now poised to become law, when President Joe Biden signs it Wednesday.
The bill offer the app's Chinese-based parent company two choices: Sell the app or see it shut down, sometime between next January and April, in its biggest national market.
This sets up a year of intense battles on multiple fronts in courtrooms, boardrooms and the presidential election trail.
Here's a summary of the situation.
What just happened
Late Tuesday evening, in a 79-18 vote, the U.S. Senate passed a major national-security bill that arms America's allies and sanctions adversaries.
The biggest immediate story in the bill is the long-awaited weapons delivery to Ukraine — a months-long resupply intended to halt Russian advances.
About two-thirds of the $95-billion US package is going to Ukraine's self-defence, with the remainder going primarily to weapons for Taiwan and Israel.
"Finally, finally, finally," said Senate majority leader Chuck Schumer, celebrating the end of a six-month struggle to pass this bill.
"America sends a message to the entire world: We will not turn our back on you. Tonight we tell our allies we stand with you, we tell our adversaries don't mess with us."
The Republican-led House had tucked the TikTok element into the bill, and it had overwhelming bipartisan support.
It forbids American companies from distributing, maintaining or updating apps controlled by foreign adversaries, defined as North Korea, China, Russia and Iran in an existing law.
The bill specifically singles out TikTok and its China-based parent company, ByteDance Inc.
The parent company has 270 days — meaning until Jan. 19, 2025 — to sell its product to a buyer in another country. Enforcement can be delayed another three months by the president, if there's a sale in progress.
Arguments for the TikTok crackdown
The hostile relationship between the U.S. and China is the context here: Both countries are accelerating a military buildup, and both have officials musing openly about the potential for conflict over Taiwan.
National-security hawks have persuaded a majority of the U.S. Congress that TikTok is a threat to Americans' security.
American lawmakers favouring the crackdown call it foolish to grant a Chinese-owned company control over software on the devices of 170 million Americans.
They describe two fears: One, that the app can spy on Americans, hoovering up their data. Two, that it might become an information weapon.
After a recent classified briefing on the topic, some U.S. lawmakers said they were disturbed by what they'd been told by intelligence officials.
"TikTok is a gun aimed at Americans' heads," Democratic Sen. Richard Blumenthal said afterward.
"The American people need, and deserve, to hear what we've just been told. Because they would be deeply frightened."
U.S. officials do not believe assurances that TikTok's data is kept from the Chinese government just because its servers are outside China.
Chinese law, they say, makes clear that the parent company must take orders from the central government and its representatives on ByteDance's staff.
ByteDance is even accused of helping build China's system for cracking down on the Uyghur minority, and of targeting protesters in Hong Kong.
Leaked audio from TikTok meetings shows that user data is repeatedly accessed from that parent company in China.
Meanwhile, TikTok was the only app that monitored users' phone keystrokes among seven major apps tested by a privacy researcher and former Google engineer.
The company called those findings misleading.
When asked about keystroke-monitoring at a congressional hearing last year, TikTok CEO Chew Shou Zi replied: "Only for security purposes."
He said his company only checked for bots, and said other companies do the same. He said TikTok does not monitor what users type.
Arguments against the crackdown
Up to half the U.S. uses this app. Some Americans earn a living as influencers on it, and there's no evidence it's done any of them any harm.
One user with a lot of reach is Sarah Lauren, a Canadian living in New York City. She currently has another job but is thinking of making a full-time living from TikTok revenue.
With 740,000 followers, she's drawn tens of millions of views for posts with titles like, "Things Guys Do When They Don't Like You."
"It is definitely scary," she told CBC News this week, when asked about the potential U.S. ban.
"I'm lucky because I have a full-time job as well.… But for my friends that are in content creation and they do it as a full-time job, it's really crucial for our income. To be banned, what are they gonna do?"
She advises her fellow influencers to start hedging their bets by posting on all platforms, including Instagram where she has about 40,000 followers.
If the U.S. government has evidence that these Americans are at risk, it should show its cards, says one free-speech advocate.
"Currently, there is no public evidence that TikTok has shared user data with the Chinese government," said Kate Ruane, director of the Center for Democracy and Technology's Free Expression Project.
Furthermore, she said, foreign adversaries have other ways to scoop up Americans' personal data: They can simply buy it on the open market.
That's why she's urged the U.S. Congress to pass comprehensive legislation regulating the data economy, instead of just targeting one company.
For example, she pointed to the American Privacy Rights Act. The still-unpassed bill would limit what platforms can collect, and sell to data-brokers, without user consent. It would let users learn more about what data is collected, be able to opt out, force data sellers to be publicly transparent and would give state and federal authorities more power to punish abuses.
Separately, there's a bill in the Senate — the Kids Online Safety Act — that would force sweeping reforms across the industry, intended to protect young users.
Next up: Big battles
International companies will surely make big offers to buy this hot digital commodity. But the Chinese government has hinted it would block a sale.
The superpowers will accuse each other of hypocrisy.
China, after all, is now crying foul, but it bans U.S. products like Google, Facebook, X and Instagram. The U.S., meanwhile, will be accused of selective commitment to free speech.
The inevitable lawsuits could lead to the U.S. Supreme Court.
A Montana case offers a preview of the arguments. When the state of Montana passed a TikTok ban last year, the company sued.
The company argued the ban violated multiple clauses of the U.S. Constitution. The free-speech protections in the First Amendment, for starters.
It also cited the so-called bill of attainder clause in Article 1, which forbids assigning guilt and punishing someone in a law without a trial.
A federal judge has temporarily blocked Montana's ban: "[This] likely violates the First Amendment," wrote district court Judge Donald Molloy.
Finally, there's the presidential election.
Donald Trump has done a head-snapping, 180-degree turn. He tried unilaterally banning TikTok when he was president, but was rebuked by the courts; now he's on good terms with a major campaign donor who is also a major shareholder in TikTok.
Trump has suddenly transformed himself into a TikTok champion.
And he's been transparent in how he intends to use this on the campaign trail: To try peeling young voters away from Biden in a close election.
"Young people, and lots of others, must remember this … when they vote," Trump posted on his own social-media site, blaming Biden for a potential ban.
When Schumer, the Democratic congressional leader, was asked Tuesday about possible political blowback, he recited the history of the bill.
It was the Republican-led House that passed a TikTok ban last month. That bill was idling in the Senate. Then the Republican House passed it again Saturday, he noted.
This time the measure was stuck into a bigger bill the Senate was desperately keen on passing: Aid for Ukraine, in particular, which had been stalled for months.
Four days later, it's on its way to the president's desk. And the countdown starts to a potential ban as soon as Jan. 19, 2025 — the last full day of Biden's current term.
