The Treasury Department on Monday imposed sanctions against Tornado Cash, a popular cryptocurrency platform known as a mixer because it blends funds from different users and redistributes them, obscuring their origin. The Treasury Department accused Tornado Cash of laundering billions of dollars in virtual currency, including $455 million allegedly stolen by North Korean hackers. As part of the penalties, officials blocked all property held by the exchange under U.S. jurisdiction and barred U.S. companies and individuals from transacting with it.

https://www.wsj.com/articles/tornado-cash-crackdown-shows-limits-of-regulating-cryptocurrency-services-11660220579