Treasury says mixing is money transmission so if you were a US person operating such a service you’d need a MSB license and a license for the states you operat

Treasury says mixing is money transmission so if you were a US person operating such a service you’d need a MSB license and a license for the states you operate in. Tornado Cash had no US persons operating it (arguably no one was operating it as it cannot be shutdown and does not take fees) and really no US nexus so they just used sanctions instead of criminal or civil charges to get their way.