There are a few steps to running code on Ethereum: 1. A person writes the source code and shares it 2. A person pays a flat amount of ETH to compile/instantia

There are a few steps to running code on Ethereum: 1. A person writes the source code and shares it 2. A person pays a flat amount of ETH to compile/instantiate the source code on the Ethereum network. The code is not "running" yet (aside from its constructor function, if it has one). Now the code is instantiated at an Ethereum address. 3. A person invokes a function of the code, paying ETH proportional to the amount of execution steps taken before the function returns. 4. A swarm of computers acting as block producers, some with identifiable operating persons and some without, produce a block that officially timestamps that function execution into the chain and applies it to the chain's state. 5. A swarm of computers acting as network observers, some with identifiable operating persons and some without, re-execute the transaction locally to verify that the state change was valid. > the people picking up the phone and asking the system to launder money Of course, culpability there goes without saying. That's not relevant to the question of whether Tornado Cash is illegal, it's a question of whether crime itself is illegal; in essence a tautology. > as well as those responsible for the specific instances of the code that are doing the laundering It looks like you may be talking about the second step of the five I've laid out. That step, the instantiation of the code, can be done anonymously from anywhere in the world by anyone who can follow the compilation instructions in the readme. If that's the step where legislators try to enforce culpability, it's a lost cause due to the anonymity. Hypothetically, even if law enforcement were able to perfectly determine the legal owner of every Ethereum address and punish them when they illegally instantiate code, they still can't cause the code to be un-instantiated.