Only two months ago Joe Biden joined the social media platform TikTok with a video captioned "lol hey guys". Now, the US president is poised to sign a bill that could ban the popular app - unless its parent company sells it.    The country is concerned that TikTok's owner, Beijing-based tech firm ByteDance, could be forced by Chinese authorities to hand over the user data of almost 170 million American app users.    On this episode, Niall Paterson unpicks the possible ban with Arthi Nachiappan, our technology correspondent. Plus, Chris Stokel-Walker, author of TikTok Boom: China's Dynamite App And The Superpower Race For Social Media, joins Niall to discuss the app's impact in the US - as well as China's influence on technology. Since recording this episode, TikTok CEO, Shou Chew said in a statement: "This unconstitutional law is a TikTok ban, and we will challenge it in court. We believe the facts and the law are clearly on our side, and we will ultimately prevail."As we continue to challenge this unconstitutional ban, we will continue investing and innovating to ensure TikTok remains a space where Americans of all walks of life can safely come to share their experiences, find joy, and be inspired."Producer: Emma Rae Woodhouse Assistant producer: Iona BrunkerPromotions producer: David Chipakupaku Editor: Paul Stanworth