I believe what they're saying is - we have the capability to track every physical banknote as it leaves/enters the bank and attach it to the person who deposits/withdraws it.
There may be extra steps in between, but if you're tracking a transaction / relationship type which happens twice or more, you can expect that the person on the record is the person you're after or can point you at them.
But I don't know why they expect FBI to actually have it implemented. The system would have to be so widespread/common that we'd know if it existed. I mean, there's https://en.wikipedia.org/wiki/Currency_bill_tracking but that's for hobbyists. Otherwise banks may check for duplicate numbers... but I can't find any mention of more widespread tracking.
The person who made this point addressed this already:
> banknotes are only in circulation for one or two exchanges before coming back to a bank
No, you don't get the 100% whole picture, but you can mine a ton out of data points like "note 38573204 was given to John Doe via ATM on 2023-01-10, and returned to bank by Jane Smith (owner of ABC Widgets) on 2023-01-14".
Many people don't, but businesses deposit excess cash daily.
Certainly, though, those same businesses keep a lot of cash in order to give change to other customers. But that cash will still likely end up back at a bank before too long.
There may be extra steps in between, but if you're tracking a transaction / relationship type which happens twice or more, you can expect that the person on the record is the person you're after or can point you at them.
But I don't know why they expect FBI to actually have it implemented. The system would have to be so widespread/common that we'd know if it existed. I mean, there's https://en.wikipedia.org/wiki/Currency_bill_tracking but that's for hobbyists. Otherwise banks may check for duplicate numbers... but I can't find any mention of more widespread tracking.