Thousands of American users set up accounts on the increasingly popular app Xiaohongshu just days before U.S. law is set to go into into effect

The justices are expected to rule quickly in the case, which pits national security concerns about China against the First Amendment’s protection of free speech.

The Supreme Court seems likely to uphold a law that would ban TikTok in the United States beginning Jan. 19 unless the popular social media program is sold by its China-based parent company.

TikTok remains on schedule to be banned in the U.S. beginning Sunday, one day before President-elect Donald Trump takes office. In high-pressure hearings last Friday, the Supreme Court appeared likely to rule in favor of the ban.