While Tornado Cash had a website with user-friendly interface, on which, technically, it was possible to implement know your customer/anti-money-laundering (KYC/AML) features (even considering the absurdity of such an idea for a crypto mixer), its smart contracts code is open source. Users can deploy it without going to a specific website as well as copy it and clone the service, using other, not-yet-sanctioned wallets.
Crypto Sanctions & Their Impact on the Cryptocurrency Ecosystem – Crypto 2023
