From a legal standpoint, understanding what Tornado Cash does may be less important than understanding what it is. It is not a company or a human or even a machine with a physical presence. It is open-source code – text, commands, numbers and words – that executes a certain scheme of commands when compiled and deployed in its intended environment.

Tornado Cash, then, is a network of peer-to-peer channels, rather than a discrete company, entity or service. So while the sanctioning document targets Tornado Cash by name, and lays out a series of specific Ethereum addresses associated with it, the code could in principle be redeployed under a different name and utilizing different addresses. It seems likely this would set up a kind of “whack-a-mole” situation as new iterations of Tornado Cash are sanctioned as quickly as they appear.

That could hint at why someone may have leaned on Github owner Microsoft (MSFT) to ban Semenov. The real threat here isn’t the operational Tornado Cash service on Ethereum, but the infinitely and freely replicable code that makes it work.

As the Washington, D.C., lobbying group Coin Center has pointed out, various legal judgments have concluded that both money and computer code can be forms of speech protected by the First Amendment.

This is a fundamental dilemma for the U.S., and even for global jurisprudence and social structure.