If you just spent a few bucks on groceries once, then you are in the clear. But if you get doing it repeatedly, or worse, spent a whole bunch of cash to buy a c

If you just spent a few bucks on groceries once, then you are in the clear. But if you get doing it repeatedly, or worse, spent a whole bunch of cash to buy a car or something expensive, then when that money did get back to a bank then eventually those numbers will be identified and FBI will be notified. If you are trying to spend $20 or $100 in marked bills, you'd be fine. But try that with 4 million in $100 bills, it won't take long for them to find you. Not instantly, but eventually.