[code_duck]

The last time I with Drew a large sum from the bank, he did run it through accounting machine and most of those have OCR abilities.

Businesses I've been involved with write down the serial numbers of high denomination bills when cash drawers are filled. I wouldn't be surprised if banks were aware of which serials were in their cash drawers for inventory purposes basically.

It's true that the only real tracking that goes on with serial numbers currently to catch criminals is recorded cereals in bank robberies and black market transactions. However, the capability is there to construct some small amount of conclusions about regular people based on where bills go. I wasn't saying it's widely in use for everyday surveillance.