Here’s how TikTok went from a teen sensation to Washington’s boogeyman:1. September 2016Sept. 26In China, ByteDance launches the lip-syncing social media app Douyin, the predecessor of what would become TikTok. July 31Trump says he plans to bar TikTok from operating in the United States because of national security concerns16. June 2021June 9President Biden revokes Trump’s TikTok ban but sets up a security review of foreign-owned apps. December 2022Dec. 14The Senate passes a bill to ban federal employees from using TikTok on government devices.