According to the law, Trump cannot unilaterally give a 90-day extension unless ByteDance guarantees to him that it will sell the app to an American company. On Jan. 18, TikTok went dark ahead of a federal ban on the app set to take effect the following day ...

Just hours after going dark, TikTok is back online—though nothing, legally, has changed. Just after midnight on Sunday, the popular but maligned Chinese-owned app ceased operation in the United States; users logging on received a message that the service ...