The problem was that Tether, like other cryptocurrencies, broke just about every rule in banking. Banks keep track of everyone who has an account and where they send their money, allowing law enforcement agencies to track transactions by criminals. Tether would check the identity of people who bought coins directly from the company, but once the currency was out in the world, it could be transferred anonymously, just by sending a code. A drug lord could hold millions of Tethers in a digital wallet and send it to a terrorist without anyone knowing.
