What about banning end-to-end encryption while keeping client-server encryption (like Telegram or Apple does)? If people are not allowed to transfer money anonymously, why allow them communicate anonymously?
Wholesale banning of anonymous money transfers would also, in my opinion, be a violation of 1st and 4th amendments. But banning encrypted speech & communication altogether (or compelling an open-access backdoor) is clearly a violation of 1st & 4th amendment.
there's already enough cameras to capture every angle - including the ones at registers that clearly are there just to capture your face.
The only reason i can see for a cashless society is: someone is going to make shedloads of money on the microtransactions. Visa, MC, AmEx, JP Morgan, etc.
You can do that in the US though with cash. There might be some transactions that you can't do in physical cash but that is more of a practical/convince limitation and not a legal one.