I wonder...

You have just stolen an obscene amount of cash, so much that the sheer bulk of it is a problem, and far more than you can comfortably launder or spend. You take a small portion of it (still a v.large sum) and distribute it to people who do not know you, buy junk off them at stupid prices, even shove a bit through a few letterboxes. It will only take a few of your patsies to draw attention to themselves by trying to use/bank the cash and suddenly the cops are chasing down dozens of false leads, while you walk quietly away with the bulk of the loot.