The U.S. Congress has moved a big step closer to a crackdown on a popular platform that could have far-reaching implications for social media in the country.It involves a bill with major implications for the fast-growing site TikTok, renowned for addictive videos and used by hundreds of millions around the world, including millions in Canada.At issue are alleged concerns about risks to national security and young users. The counter-claim: American politicians are unfairly picking on a Chinese-ow...