To the people saying you're taking away work from the min-wagers: that's a
broken window fallacy. Creating extra work that doesn't produce anything costs the stores more, which raises prices, which costs you. It can even contribute to inflation! (Ok, so I doubt there's a huge nationwide impact from carts left, but still.) If the supermarket needs 1 less kid grabbing carts, he can go work at McDonalds for the same pay.