The Supreme Court today will hear arguments on the banning of TikTok in the U.S., marking “one of the most important cases of the social media age, free speech and national security.” A decision on the matter “could come within days.” TikTok said that it “plans to shut down” in the U.S. by Jan. 19 unless the Supreme Court “strikes down or otherwise delays” the effective date of a law aimed at forcing TikTok ’ s sale by its Chinese parent company. The justices are also handling a plea from President-elect Donald Trump , who has “dropped his earlier support for a ban,” to give him and his new administration “time to reach a ‘ political resolution ’ and avoid deciding the case.” If the law takes effect, Trump’s Justice Department will be “charged with enforcing it.” Lawyers for TikTok and ByteDance have argued that the new administration could “seek to mitigate the law’s most severe consequences” ( AP, 1/9 ).