Molly White

It's interesting to me that the Fifth Circuit only considered "control" at the smart contract level, and does not seem to consider the role of validators in their opinion. A substantial portion of ETH blocks are built with relays that censor transactions with OFAC-sanctioned contracts, and it seems to me there is now an open question as to whether validators that use non-censoring relays could be sanctioned directly.

The software codes here—the twenty Tornado Cash addresses for immutable smart contracts—are tools used in providing a service of pooling and mixing the deposited Ether prior to withdrawal. Indeed, the immutable smart contract provides a “service” only when an individual cryptocurrency owner makes the relevant input and withdrawal from the smart contract; at that point, and only at that point, the immutable smart contract mixes deposits, provides the depositor a withdrawal key, and, when provided with that key, sends the specified amount to the designated withdrawal account. In short, the immutable smart contract begins working only when prompted to do so by a deposit or entry of a key for withdrawal. More importantly, Tornado Cash, as defined by OFAC, does not own the services provided by the immutable smart contracts. A homeowner may own the right to trash-removal services and a client may own the right to legal services performed by a lawyer, but neither the homeowner nor the client owns the person performing the trash-removal services or the lawyer—for good reason. Similarly, Tornado Cash as an “entity” does not own the immutable smart contracts, separate and apart from any rights or benefits of the services performed by the immutable smart contracts.76

(Not saying they should, just remarking on the fact that it seems to have gone completely unaddressed.)

Of course this was a concern already, but what with the Treasury focused on the Tornado Cash contracts, it was less central than I suspect it might be soon. This strategy would be somewhat in keeping with legal theories around other "malicious" code, where it's broadly speaking legal to write a devastating computer virus, but a whole lot less legal to run one.