Through attacking the link between cryptocurrencies and the fiat banking system. It really doesn't matter if you can trade $10MM of bitcoin for $10MM of ethere

Through attacking the link between cryptocurrencies and the fiat banking system. It really doesn't matter if you can trade $10MM of bitcoin for $10MM of ethereum if after doing so you are unable to pay your rent with it. Throw some KYC/AML laws on accepting cryptocurrency deposits so that it's treated like a cash deposit for regulatory purposes. Accept as a regulator that a lot of small-time stuff is going to slip through the cracks, in exchange for making gross violations problematic. Like, if you could fit ten million dollars in cash in your pockets, you'd already have trouble getting it into your bank account without a rock-solid explanation as to how you got it. Bitcoin etc is no different - the US government can avoid caring until you try to spend dollars, then nab you for violating regulations.