The app had more than 170 million monthly users in the U.S. The black-out is the result of a law forcing the service offline unless it sheds its ties to ByteDance, its China-based parent company.

The Supreme Court has unanimously upheld the federal law banning TikTok beginning Sunday unless it’s sold by its China-based parent company.

Justices reject the Chinese app’s First Amendment challenge to a federal law against “foreign adversary” control.