The court is hearing oral arguments on TikTok’s bid to block a law that would lead to its ban in the U.S. starting Jan. 19 if it isn’t sold by its Chinese owner.

A majority of the Supreme Court appeared likely to uphold a controversial ban on TikTok over concerns about its ties to China, with justices lobbing pointed questions at lawyers for the social media app and a group of its content creators.

The justices, who asked tough questions of both sides, showed skepticism toward arguments by lawyers for TikTok and its users.