TikTok has argued that the law violates the First Amendment rights of its over 170 million U.S. users, while the U.S. government made the case that ByteDance's ownership and its alleged ties to the People's Republic of China make the app a national security risk. The Supreme Court sided with the Biden administration in January, and, in an opinion, said, "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."
TikTok pushed back on the Supreme Court's decision, and followed through with its threat to shut down its U.S. operations unless the Biden administration intervened.