ATM -> retailer -> back to the bank in the evening.
I once made a calculation of whether it is possible to track all banknotes by serial number. There are only 20bn EU banknotes! Fits snuggly in a Postgres DB.
With that, you could detect patterns: Does these guys always withdraws from this ATM and the money is cashed in that other neighborhood? Drug deal. A banknotes suddenly reappears after years? Black money stored in bulk, let’s see who withdrew it. Etc.
I once made a calculation of whether it is possible to track all banknotes by serial number. There are only 20bn EU banknotes! Fits snuggly in a Postgres DB.
With that, you could detect patterns: Does these guys always withdraws from this ATM and the money is cashed in that other neighborhood? Drug deal. A banknotes suddenly reappears after years? Black money stored in bulk, let’s see who withdrew it. Etc.