There are two rather popular mechanisms. One is simply using crypto as cash equivalent - a mechanism to receive (and spend) undeclared income without paying th

There are two rather popular mechanisms. One is simply using crypto as cash equivalent - a mechanism to receive (and spend) undeclared income without paying the relevant taxes, so that drives adopting pretty much the same regulations as for cash, just as there already are various requirements to declare and deanonymize large cash transaction, the same gets implemented for various crypto-assets. The other is using NFTs (or similar products) for money laundering, again in pretty much the same way as physical art can be used; the key steps being (a) cheaply buy or make some asset-with-undefined-value; (b) have an "anonymous customer" (your own 'sockpuppet') buy it from you at a high price using cash or cryptocurrency. This can be both a form of partial tax evasion, as the capital gains tax you'd pay on this profit is often much lower than what you'd pay otherwise for that income, and also a form of money laundering, if the funds are obtained, for example, from some scam or ransomware operation. And again, the general solution here is to apply the same regulations as for large quantities of cash, such as requiring to identify the counterparty and thus make the potential laundering traceable.