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’s remarkably speedy decision Friday to allow a controversial ban on TikTok to take hold will have a dramatic impact on the tens of millions of Americans who visit the app every day and broad political implications for President-elect Donald Trump.

TikTok is set to be banned in the US on 19 January after the Supreme Court denied a last ditch legal bid from its Chinese owner, ByteDance. It found the law banning the social media platform did not violate the first amendment rights of TikTok and its 170 million users, as the companies argued.