Tornado.cash is decentralized software, and there is no law that can be envoked to prohibit people from using it for their own transactions, unless it can be proven their own transactions are illicit in origin, in which case they can already be booked for the original crime.
This is of course how it should be. We don't need AML laws as any case of money laundering would require an underlying crime that generated the illicit revenue, and proving that crime occurred - which is a prerequisite for proving money laundering occurred - would be sufficient to put that criminal behind bars.
And what we have now are financial surveillance laws misnamed anti-money laundering laws. Their purpose is not to criminalize actual money laundering, which is redundant for reasons just explained. Their purpose is to criminalize services that protect their clients' financial privacy, by:
* not demanding they disclose private financial information to prove their transactions are non-criminal in origin before facilitating them (providing presumption of innocence)
* not requiring them to disclose personal information (KYC) before facilitating their transactions, and
* not reporting that personal information to government surveillance agencies without a warrant (e.g. FinCEN reporting requirements).
I think every one welcomes stopping the flow of illicit revenue, but efforts to accomplish that should not come at the expense of core principles of a free society, like the right to privacy, and the presumption of innocence.
This is especially so given there is considerable evidence that so-called AML laws are highly ineffective despite all the costs they impose in both financial terms and in terms of basic rights:
https://www.tandfonline.com/doi/full/10.1080/25741292.2020.1...