A TikTok ban might be one step closer to reality even if there are still some lingering doubts about whether a federal law will really go into effect on January 19.

Congress labeled the app’s Chinese ownership a national security risk and passed a law that would ban the social media platform unless it was sold. TikTok and creators say that violates their free speech rights.

The court heard 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.