A federal appeals court has upheld a law that could ban TikTok from the US unless its Chinese parent company, ByteDance, divests the popular video app. The ruling, handed down by a panel of judges for the DC Circuit Court of Appeals, is a significant blow to TikTok's efforts to remain operational in the country.

The law in question, which was passed with overwhelming bipartisan support in both chambers of Congress, gives ByteDance until January 19th to sell TikTok or face its expulsion from the US. The deadline now falls one day before President-elect Donald Trump will be inaugurated for the second time, sparking speculation about his potential response to the ruling.

During his first term, Trump sought to ban TikTok, but he changed his tune on the campaign trail this year, suggesting that a ban would only benefit Meta, a rival social media platform. However, Trump allies reportedly expected him to try to halt the ban, and the options for recourse are somewhat limited. The law allows for a 90-day extension at the president's discretion, but only if progress is being made toward a spin-out. Alternatively, Trump could direct the Department of Justice not to enforce the bill, but that would still leave app store companies like Google and Apple in a precarious spot, should Trump change his mind or a future administration decide to enforce the law.

The court's decision was based on the conclusion that the law could survive even strict scrutiny under the First Amendment, and did not find TikTok's arguments that it violates equal protections under the Fifth Amendment compelling. In the opinion for the court, Judge Douglas Ginsburg wrote, "We emphasize from the outset that our conclusion here is fact-bound... The multi-year efforts of both political branches to investigate the national security risks posed by the TikTok platform, and to consider potential remedies proposed by TikTok, weigh heavily in favor of the Act."

The national security risks cited by the court include fears that China could use TikTok for data collection and covertly manipulate the recommendation algorithms. Proponents of the law argue that it is necessary to protect the privacy of Americans and prevent foreign influence campaigns. Chinese law allows the government to compel companies headquartered there to hand over internal information for national security reasons, sparking concerns that Chinese officials could have a say in what information Americans do and don't see.

During oral arguments in September, TikTok and a group of creators also suing to block the law argued that it would stifle Americans' speech and unfairly limit the information they're able to access. The DOJ defended the law as appropriately tailored to address a national security risk. The three-judge panel that heard the case appeared skeptical of the company's arguments, prodding at the practicality of a more restrained approach.

The ruling could still be appealed en banc to the full panel of judges on the DC Circuit, and ultimately to the Supreme Court. However, the decision raises significant uncertainty about TikTok's future in the US, and the potential implications for its millions of users and the broader tech industry.