I don't know how legal this may be - I suppose it varies by country. Probably not legal in the US at least. Regardless, it seems rather inefficient. The goal of the property owner is to keep the property free of cars. If someone parks and they deflate the tires, doesn't that make it harder to move the car? In the US the standard remedy is for the property owner to call a towing company. The towing company will remove the car at no cost to the property owner. In order to recover the car, the car owner will be forced to pay a fee to the towing company, covering the cost of towing. Which is roughly comparable to paying a fine. Except of course that it's hard to refuse to pay, since otherwise you don't get the car back.