I'm sure this will devolve into trolling for petty crime and dragnet surveillance. The dude who carries a gun because he has to carry a ton of cash to fill up ATMs (edit: we're talking about the ATM at the hole in the wall convenience store, or the smoke shop, not the bank) will be arrested (I'm sure they'll take the cash too) but no terrorists will be caught. Unless they've got detection, assessment and response down to a few minutes or less this wouldn't even stop a suicide bomber or gunman unless they can't be bothered to take an uber to their target, that's assuming the system detects most threats in the first place. I don't see how this defends against bombs in luggage or rolling toolboxes/cases.