This is not a criminal hiring a contractor to work on Tornado Cash. It is an open source project on GitHub that many developers and researchers contributed to, in the interest of privacy.
To use an analogy, see the open Matrix protocol, a tool for privacy that can facilitate encrypted communication between criminals.
Well, we're not seeing arrests of all the many developers and researchers who contributed to Tornado Cash simply in the interest of privacy as such (because that is not a crime), however, I presume that for this particular person there is some extra evidence establishing probable cause for the arrest.
For example, if it can be shown in court that he contributed to it with a knowing intent to facilitate privacy of illegal deals, that might be considered aiding and abetting "the concealment or disguise of the true nature, source, location, disposition, movement, rights with respect to, or ownership of, property, knowing that such property is derived from criminal activity", which is a crime under EU/Dutch AML law.
Yeah, in that case unless there are specific laws violated by the code (earlier DMCA violations come to mind) then it should be safe as I said.
But as usual things are only legal until it’s tried.
A machine that prints counterfeit bills might be illegal to make or sell even without ever being used in some jurisdictions while not in others. And whether the machine has other, legal purposes, may or may not matter.
The “dual use” thing is a common argument for most technical things when there is talk of bans and regulation. I think it’s mostly a hollow argument in cases where the primary actual users are criminal users. That some technology can be used for illegal purposes should not be enough to ban it, but nor should whether there exists a legal use for a technology be enough argument that it shouldn’t be outlawed.
You seem to believe that if a tool is illegal, as long as it's open source and the people making it don't have a criminal background, and as long as you call it something like "privacy software," somehow it's suddenly not illegal
But this is a tool whose specific purpose it is to make it difficult to track illegal transactions. Of course this is happening.
Programmers get way too wrapped up in "but I called it open source! I called it privacy software!"
What you label it has no actual power here. It was used in illegal behavior and that appears to be its goal.
Matrix protocol’s sole purpose is to obscure usernames and messages and enable privacy. Tornado Cash’s sole purpose is to obscure blockchain addresses and enable privacy. Privacy is not a crime. Using Matrix to hire a hit-man would be a crime, but we don’t sanction the Matrix protocol or it’s developers just because it can be used by criminals to obscure their crimes.
What's the practical difference between the kind of privacy Tornado Cash provides and the kind of privacy offered by a local money laundering operation? If there is none, why should the latter be illegal while the former remains legal?
One exists to facilitate privacy, the other exists to facilitate money laundering.
Compare with E2EE Matrix protocol: it does not exist to facilitate criminal communication, but it does facilitate criminal communication.
TC is also different because it is an open source protocol, not a legal entity or group. You deposit funds into the protocol, and anybody in the network can help you withdraw them by relaying your transaction. It is a set of rules that any group of people can follow to allow for private transactions, and the same protocol can run on many blockchains.
To use an analogy, see the open Matrix protocol, a tool for privacy that can facilitate encrypted communication between criminals.