riding down the freeway, a piece of hard paper/cardboard flew out of someone's window and wrapped harmlessly around my leg. I shook my leg; it wouldn't come off. I had to reach down and pull it off my leg with my hand.
Only now, I have trash in my hand...shaking your leg is one thing, but taking trash that is in your hand and throwing it into the road is an Evil. It is a Thing Which Should Not Be Done.
The obvious retort is that I didn't produce the trash, I didn't put it where it was, thus I wasn't responsible and thus I can throw it on the ground. But wait! Let's imagine a world where the car it came from was driven by someone who had given a ride to someone else, and that other person had put the trash in their car. The driver saw the trash and decided that they didn't produce the trash, they didn't put it where it was, thus they weren't responsible for it and thus they could throw it on the ground.
So I put the trash in my pocket, and threw it away when I got to work. Deep, huh. ;)