How TikTok Grew from a Fun App for Teens into a Potential National Security Threat

If it feels like TikTok has been around forever, that's probably because it has, at least if you're measuring via internet time. What's now in question is whether it will be around much longer and, if so, in what form?

Starting in 2017, when the Chinese social video app merged with its competitor Musical.ly, TikTok has grown from a niche teen app into a global trendsetter. While, of course, also emerging as a potential national security threat, according to US officials.

On April 24, President Joe Biden signed legislation requiring TikTok parent ByteDance to sell to a US owner within a year or to shut down. TikTok and its China-based parent company, ByteDance, filed a lawsuit against the US, claiming the security concerns were overblown and the law should be struck down because it violates the First Amendment.

The Supreme Court on Friday unanimously upheld the federal law banning TikTok, and the popular short form video service went dark in the US just hours before the ban was set to begin.

Here's how TikTok came to this juncture:

March 2012 ByteDance is founded in China by entrepreneur Zhang Yimin. Its first hit product is Toutiao, a personalized news aggregator for Chinese users.

July 2014 Startup Musical.ly, later known for an eponymous app used to post short lipsyncing music videos, is founded in China by entrepreneur Alex Zhu.

July 2015 Musical.ly hits #1 in the Apple App Store, following a design change that made the company's logo visible when users shared their videos.

2016 ByteDance launches Douyin, a video sharing app for Chinese users. Its popularity inspires the company to spin off a version for foreign audiences called TikTok.

November 2017 ByteDance acquires Musical.ly for $1 billion. Nine months later, ByteDance merges it with TikTok.

Powered by an algorithm that encourages binge-watching, users begin to share a wide variety of videos on the app, including dance moves, kitchen food preparation and various “challenges” to perform, record and post acts that range from serious to satirical.

February 2019 Rapper Lil Nas X releases the country-trap song “Old Town Road” on TikTok, where it goes viral and pushes the song to a record 17 weeks in the #1 spot on the Billboard Hot 100 chart. The phenomenon kicks off a wave of TikTok videos from musical artists who suddenly see TikTok as a critical way to reach fans.

TikTok settles federal charges of violating US child-privacy laws and agrees to pay a $5.7 million fine.

September 2019 The Washington Post reports that while images of Hong Kong democracy protests and police crackdowns are common on most social media sites, they are strangely absent on TikTok. The same story notes that TikTok posts with the #trump2020 tag received more than 70 million views.

The company insists that TikTok content moderation, conducted in the US, is not responsible and says the app is a place for entertainment, not politics.

The Guardian reports on internal documents that reportedly detail how TikTok instructs its moderators to delete or limit the reach of videos touching on topics sensitive to China such as the 1989 Tiananmen Square protests and subsequent massacre.

October 2019 US politicians begin to raise alarms about TikTok's influence, calling for a federal investigations of its Musical.ly acquisition and a national security probe into TikTok and other Chinese-owned apps. That investigation begins in November, according to news reports.

December 2019 The Pentagon recommends that all US military personnel delete TikTok from all phones, personal and government-issued. Some services ban the app on military owned phones. In January, the Pentagon bans the app from all military phones.

TikTok becomes the second-most downloaded app in the world, according to data from analytics firm SensorTower.

May 2020 Privacy groups file a complaint alleging TikTok is still violating US child-protection laws and flouting a 2019 settlement agreement. The company “takes the issue of safely seriously” and continues to improve safeguards, it says.

TikTok hires former Disney executive Kevin Mayer as its chief executive officer in an apparent attempt to improve its US relations. Mayer resigns three months later.

July 2020 India bans TikTok and dozens of other Chinese apps in response to a border clash with China.

President Donald Trump says he is considering banning TikTok as retaliation for China's alleged mishandling of the COVID-19 pandemic.

August 2020 Trump issues a sweeping but vague executive order banning American companies from any “transaction” with ByteDance and its subsidiaries, including TikTok. Several days later, he issues a second order demanding that ByteDance divest itself of TikTok's US operations within 90 days.

Microsoft confirms it is exploring acquisition of TikTok. The deal never materializes; neither does a similar overture from Oracle and Walmart. TikTok, meanwhile, sues the Trump administration for alleged violation of due process in its executive orders.

November 2020 Joe Biden is elected president. He doesn't offer a new policy on TikTok and won't take office until January, but Trump's plans to force a sale of TikTok start to unravel anyway. The Trump administration extends the deadlines it had imposed on ByteDance and TikTok and eventually lets them slide altogether.

February 2021 Newly sworn-in President Joe Biden postpones the legal cases involving Trump's plan to ban TikTok, effectively bringing them to a halt.

September 2021 TikTok announces it has more than a billion monthly active users.

December 2021 A Wall Street Journal report finds TikTok algorithms can flood teens with a torrent of harmful material such as videos recommending extreme dieting, a form of eating disorder.

February 2022 TikTok announces new rules to deter the spread of harmful material such as viral hoaxes and promotion of eating disorders.

April 2022 “The Unofficial Bridgerton Musical,” a project created by two fans of the Netflix show as a TikTok project, wins the Grammy for Best Musical Theater Album.

TikTok becomes the most downloaded app in the world, beating out Instagram, according to SensorTower data.

June 2022 BuzzFeed reports that China-based ByteDance employees have repeatedly accessed the nonpublic information of TikTok users, based on leaked recordings from more than 80 internal TikTok meetings. TikTok responds with a vague comment touting its commitment to security that doesn't directly address the BuzzFeed report.

TikTok also announces it has migrated its user data to US servers managed by the US tech firm Oracle. But that doesn't prevent fresh alarm among US officials about the risk of Chinese authorities accessing US user data.

December 2022 FBI Director Christopher Wray raises national security concerns about TikTok, warning that Chinese officials could manipulate the app's recommendation algorithm for influence operations.

ByteDance also said it fired four employees who accessed data on journalists from Buzzfeed News and The Financial Times while attempting to track down leaks of confidential materials about the company.

February 2023 The White House gives federal agencies 30 days to ensure TikTok is deleted from all government-issued mobile devices. Both the FBI and the Federal Communications Commission warn that ByteDance could share TikTok user data with China’s authoritarian government.

March 2023 Legislators grill TikTok CEO Shou Zi Chew at a six-hour congressional hearing where Chew, a native of Singapore, attempts to push back on assertions that TikTok and ByteDance are tools of the Chinese government.

January 2024 TikTok said it was restricting a tool some researchers use to analyze popular videos on the platform.

March 2024 A bill to ban TikTok or force its sale to a US company gathers steam in Congress. TikTok brings dozens of its creators to Washington to tell lawmakers to back off, while emphasizing changes the company has made to protect user data. TikTok also annoys legislators by sending notifications to users urging them to “speak up now” or risk seeing TikTok banned; users then flood congressional offices with calls.

The House of Representatives passes the TikTok ban-or-sell bill.

April 2024 The Senate follows suit, sending the bill to President Biden, who signs it.

May 2024 TikTok and its Chinese parent company ByteDance sue the US federal government to challenge a law that would force the sale of ByteDance’s stake or face a ban, saying that the law is unconstitutional.

June 2024 Former President Donald Trump joins TikTok and begins posting campaign-related content.

July 2024 Vice President Kamala Harris joins TikTok and also begins posting campaign-related material.

Dec. 6, 2024 A federal appeals court panel unanimously upheld a law that could lead to a ban on TikTok, handing a resounding defeat to the popular social media platform as it fights for its survival in the US. The panel of judges rebuffed the company’s challenge of the statute, which it argued had ran afoul of the First Amendment.

Dec. 27, 2024 President-elect Donald Trump asked the Supreme Court to pause the potential TikTok ban from going into effect until his administration can pursue a “political resolution” to the issue.

Jan. 17, 2025 The Supreme Court unanimously upheld the federal law banning TikTok beginning unless it’s sold by its China-based parent company, holding that the risk to national security posed by its ties to China overcomes concerns about limiting speech by the app. A ban is set to into effect on Jan. 19, 2025.

Jan. 18, 2025 TikTok users in the United States were prevented from watching videos on the popular social media platform just hours before a federal ban was set to take effect.

“A law banning TikTok has been enacted in the US,” a message in the app said. “Unfortunately, that means you can’t use TikTok for now.”

The company’s app was also removed from prominent app stores, including the ones operated by Apple and Google, while its website told users that the short-form video platform was no longer available.

The Supreme Court on Friday unanimously upheld the federal law banning TikTok beginning Sunday unless it's sold by its China-based parent company, holding that the risk to national security posed by its ties to China overcomes concerns about limiting speech by the app or its 170 million users in the United States.

A sale does not appear imminent and, although experts have said the app will not disappear from existing users' phones once the law takes effect on Jan. 19, new users won't be able to download it and updates won't be available. That will eventually render the app unworkable, the Justice Department has said in court filings.

The decision came against the backdrop of unusual political agitation by President-elect Donald Trump, who vowed that he could negotiate a solution and the administration of President Joe Biden, which has signaled it won't enforce the law beginning Sunday, his final full day in office.

Trump, mindful of TikTok’s popularity, and his own 14.7 million followers on the app, finds himself on the opposite side of the argument from prominent Senate Republicans who fault TikTok’s Chinese owner for not finding a buyer before now. Trump said in a Truth Social post shortly before the decision was issued that TikTok was among the topics in his conversation Friday with Chinese leader Xi Jinping.

It’s unclear what options are open to Trump once he is sworn in as president on Monday. The law allowed for a 90-day pause in the restrictions on the app if there had been progress toward a sale before it took effect. Solicitor General Elizabeth Prelogar, who defended the law at the Supreme Court for the Democratic Biden administration, told the justices last week that it's uncertain whether the prospect of a sale once the law is in effect could trigger a 90-day respite for TikTok.

“Congress has determined that divestiture is necessary to address its well-supported national security concerns regarding TikTok’s data collection practices and relationship with a foreign adversary,” the court said in an unsigned opinion, adding that the law “does not violate petitioners' First Amendment rights.”

Justices Sonia Sotomayor and Neil Gorsuch filed short separate opinions noting some reservations about the court's decision but going along with the outcome.

“Without doubt, the remedy Congress and the President chose here is dramatic,” Gorsuch wrote. Still, he said he was persuaded by the argument that China could get access to “vast troves of personal information about tens of millions of Americans.”

Some digital rights groups slammed the court’s ruling shortly after it was released.

“Today’s unprecedented decision upholding the TikTok ban harms the free expression of hundreds of millions of TikTok users in this country and around the world,” said Kate Ruane, a director at the Washington-based Center for Democracy & Technology, which has supported TikTok’s challenge to the federal law.

Content creators who opposed the law also worried about the effect on their business if TikTok shuts down. “I’m very, very concerned about what’s going to happen over the next couple weeks,” said Desiree Hill, owner of Crown’s Corner mechanic shop in Conyers, Georgia. “And very scared about the decrease that I’m going to have in reaching customers and worried I’m going to potentially lose my business in the next six months.”

At arguments, the justices were told by a lawyer for TikTok and ByteDance Ltd., the Chinese technology company that is its parent, how difficult it would be to consummate a deal, especially since Chinese law restricts the sale of the proprietary algorithm that has made the social media platform wildly successful.

The app allows users to watch hundreds of videos in about half an hour because some are only a few seconds long, according to a lawsuit filed last year by Kentucky complaining that TikTok is designed to be addictive and harms kids' mental health. Similar suits were filed by more than a dozen states. TikTok has called the claims inaccurate.

The dispute over TikTok's ties to China has come to embody the geopolitical competition between Washington and Beijing.

“ByteDance and its Chinese Communist masters had nine months to sell TikTok before the Sunday deadline,” Sen. Tom Cotton, R-Ark., wrote on X. “The very fact that Communist China refuses to permit its sale reveals exactly what TikTok is: a communist spy app. The Supreme Court correctly rejected TikTok’s lies and propaganda masquerading as legal arguments.”

The US has said it’s concerned about TikTok collecting vast swaths of user data, including sensitive information on viewing habits, that could fall into the hands of the Chinese government through coercion. Officials have also warned the algorithm that fuels what users see on the app is vulnerable to manipulation by Chinese authorities, who can use it to shape content on the platform in a way that’s difficult to detect.

TikTok points out the US has not presented evidence that China has attempted to manipulate content on its US platform or gather American user data through TikTok.

Bipartisan majorities in Congress passed legislation and Biden signed it into law in April. The law was the culmination of a yearslong saga in Washington over TikTok, which the government sees as a national security threat.

TikTok, which sued the government last year over the law, has long denied it could be used as a tool of Beijing. A three-judge panel made up of two Republican appointees and a Democratic appointee unanimously upheld the law in December, prompting TikTok’s quick appeal to the Supreme Court.

Without a sale to an approved buyer, the law bars app stores operated by Apple, Google and others from offering TikTok beginning on Sunday. Internet hosting services also will be prohibited from hosting TikTok.

ByteDance has said it won’t sell. But some investors have been eyeing it, including Trump’s former Treasury Secretary Steven Mnuchin and billionaire businessman Frank McCourt. McCourt’s Project Liberty initiative has said it and its unnamed partners have presented a proposal to ByteDance to acquire TikTok’s US assets. The consortium, which includes “Shark Tank” host Kevin O’Leary, did not disclose the financial terms of the offer.

McCourt, in a statement following the ruling, said his group was “ready to work with the company and President Trump to complete a deal.”

Prelogar told the justices last week that having the law take effect “might be just the jolt” ByteDance needs to reconsider its position.

How TikTok Grew from a Fun App for Teens into a Potential National Security Threat