I'm firmly on the "two 'wrongs' don't make a 'right'" bench on this one. I do think it's wrong to leave a cart loose in a parking lot if you are capable of/able to return it. But I think it's also wrong to harass strangers over a non-secured cart.
A.) Runaway carts hit cars. It happens frequently. Sometimes it's as minor as scratched paint. Other times it can be more--like a smashed light. I've had both types of damage happen to my car.
B.) In some situations it can be even more dangerous, because loose carts can actually make their way out unto streets. We have a local store that's up on a hill and the carts gain enormous speed leaving the parking lot, and they cannot be seen by people in the road. Every so often when you're there you hear the "Smash!" of one of the carts hitting the guardrail on the other side of the street, and I am always relieved when I realize that the cart made it across the road without hitting a car, bike, or pedestrian.
C.) No one like finding a spot and starting to pull on, only to see there's a cart in the middle of it. Many times it's not much of a big deal to hop out of the car quickly and move the car until you finish parking, but in plenty of other cases it does cause more of an inconvenience.
I get that for some folks it's not easy to walk any more than they need to, and that other factors may make it especially hard for you in certain situations----a problem with someone who is with you, needing to leave quickly because you've just received a call about something you need to attend to immediately, etc., which is why I specifically feel one should return it if they are
able.
That being said, I firmly believe that many folks (in my area, anyway) leave them loose just because they don't feel like returning them, and I make that deduction based on stores like Aldi, where the addition of one quarter magically keeps the parking lot free of loose carts. If I shop at 3 or 4 stores, all within a tenth of a mile of one another, and every lot but Aldi's has loose carts, that leads me to believe that people are deciding a quarter is worth returning their cart, but being courteous to others is not worth returning their cart. And at Aldi, you have to bring the cart back to the building. So it's a bigger pain than the store lots with a dozen corrals all about them.

I do no believe that by some strange miracle the customers at Aldi are all magically more capable of returning their carts. I've seen some people who looked like they could barely keep themselves up still taking their cart back at Aldi.
Anyway, despite that oration on my feelings about cart returning

I think harassing people and slapping things onto their cars is not only rude and unnecessary, but stupid and dangerous as well. It takes just the wrong person being confronted to wind up with people in prison or someone injured or worse. I have no way of knowing why any given person doesn't return their cart and neither does anyone else. But even if we could be assured that the person stood there and thought "I'd like to tick people off and damage cars, so I'm leaving this right here! Hahahaha!!!"

I still don't think anyone has the right to do anything to the cart abandoning shopper. There's a much easier method of fixing the problem of a loose cart---take it back yourself.

I do it all the time, and I'm fat with asthma and a bad knee.
