Over here in Germany using a shopping cart “costs” between 50 Cents and 2 €. You have to put a coin in them to release the chain by which they are attached to eachother. Of course when you return the cart and close the lock you get your coin back.
Little metal plates without monetary value but still the right size are common marketing gifts by companies and organizations yet they still provide mostly the same unconscious effect of “I want my coin back”.
Of course there are also people who use little gadgets to unlock the carts without putting anything in but I wouldnt know about such things…
Happened before in the US IIRC.
Also, idiocy is universal.