There is a finite amount of money in circulation and the bills are numbered. It is a very traceable currency, even though it is not being traced. Simple use ima

There is a finite amount of money in circulation and the bills are numbered. It is a very traceable currency, even though it is not being traced. Simple use image recognition when it is deposited or withdrawn from a bank and record the customer doing the transaction. [BANK A]->[CUST A]->???->[CUST B]->[BANK B]. If someone is laundering money or using it in a criminal operation you will likely see patterns in the flows. It would lead to behavior of withdrawing money at an ATM then spending it to disassociate it from yourself by getting change. What if they build in scanning to cash registers though? Seems relatively simple to track cash if there was any will to do so.