Earlier quoted context omitted.
That covers you publishing software. It doesn’t cover providing a service to criminals and personally profiting from it, and the constitution definitely gives the government authority to police that so it’s going to come down to how well they can prove that those guys were going more than just releasing code.
The tornado cash smart contracts simply encrypt your transaction. When you use it you are not profiting off of it. It would be akin to banning. The use of communication encryption protocol period this is completely unprecedented in the US.
That last part is potentially defensible – bankers aren't charged just because a criminal stores money in a checking account – except that each KYC law not followed is not only its own offense but also a chance for prosecutors to argue that the decision not to do so was intentional and the operators knew their service was predominantly used by criminals. That's going to be an interesting case with potentially significant implications for the entire field.