Humans used to kill each other all the time. Now it rarely happens (directly), because of a system of crime and punishment. By nature, individuals were sick of being attacked, so they created a system to protect themselves.
That said, you probably meant it is foolish to think you can change human nature from the top-down. Justice may be enforced top-down, but obviously its origins are from the the very grassroots up. Just because you weren't alive when it happened doesn't mean your nature as a person wasn't affected by the justice system, or political system, or that the it was a foolish endeavour.
If you can come up with a system which is so beneficial that even those people who profiting from the status-quo would want to switch to it, then you can change human nature.
At Loblaw's our President's Choice gift cards need to be peeled out of the frame they are inset into, with backing. There's no way to get anything off of the card until then. Plus the frame holds the little hole so you can hang them on the shelf.
And phone cards all just have identical barcodes. The POS system then generates their activation code upon confirmation of payment, and prints it on their receipt.
This is in little ol' Canada, by the way.
"Gotcha, you snot-necked weenies!" -- Post Bros. Comics