In an executive order signed on January 20, President Donald Trump instructed the US attorney general to pause enforcement of the US ban on TikTok for 75 days while his administration decides the platform's future. US officials and lawmakers have long been concerned that TikTok's ownership by the Chinese company ByteDance poses a threat to national security. Under a federal law passed in Congress last year and upheld by the Supreme Court last week, ByteDance was required to sell the platform to an approved buyer by January 19 or face a nationwide ban. On the evening of January 18, a few hours before the ban took effect, TikTok became unusable for US users. But it came back online the following day, after Trump said on social media he would order the ban to be paused. However, Trump's order could face legal challenges because he does not have the power to overturn a law that Congress has passed and the Supreme Court has upheld. Nevertheless, Trump's order will buy time for ByteDance and TikTok to figure out their next move. Trump has proposed terms in which the US would have a 50% stake "in a joint venture" with ByteDance, but it was unclear how this would work. Trump has also not addressed whether he will allow ByteDance to keep controlling the algorithm that controls what users see on TikTok. The algorithm is maintained by ByteDance engineers in China and is one of the main concerns among supporters of the law. After the law was passed last year, ByteDance fought a legal battle against it for months. ByteDance and TikTok have not said whether they are willing to cut ties with each other within the new 75-day extension period. On January 21, Trump was asked whether he's installed the app on his phone. The US government has banned it from federal devices due to concerns it could lead to spying by Chinese intelligence agencies.