TikTok will be in federal court on Monday, aiming to block a new law that will ban the popular video app in the United States early next year.

TikTok faces an uphill battle to avoid a US ban if its Chinese owner doesn’t sell the wildly popular social media app, judging from a grilling by an appellate court panel.

Under the law, ByteDance would have to sell TikTok — a sale that the Chinese government has said is illegal under Chinese law — or see it banned in the United States as of January 19, 2025. ByteDance, TikTok, and “creators” who post on the app have challenged the law, arguing (among other things) that it violates the First Amendment.