WASHINGTON: The Supreme Court upheld on Friday a law banning TikTok in the United States on national security grounds if its Chinese parent company ByteDance does not sell it, putting the popular short-video app on track to go dark in just two days. The court’s 9-0 decision throws the social media platform — and its 170 million American users — into limbo, and its fate in the hands of Donald Trump, who has vowed to rescue TikTok after returning to the presidency on Monday.