"This is a limit on any American who wishes to use her own money and a freely available software tool to maintain her own privacy—including for otherwise entirely legal and personal reasons."

"...an American who is sent money through the Tornado.cash address is not even able to reject the transaction, and yet may be, at that moment, technically in violation of OFAC rules."

https://www.coincenter.org/u-s-treasury-sanction-of-privacy-tools-places-sweeping-restrictions-on-all-americans/