The blackout began just hours before the law took effect. Apple said in a statement on its website that TikTok and ByteDance apps are no longer available in the U.S. and visitors to the country could have limited access.

It is true that the ban, running under the legislation titled "Protecting Americans from Foreign Adversary Controlled Applications Act," has run on the grounds that the app poses "a national-security threat of immense depth and scale," according to the U.S. Justice Department .