Sorry, I can't totally go along with this.
I do agree that it's annoying, though. Sometimes, it is hard to get into and out of your car, if you are parked next to somebody like that. And sometimes, they will take two places, leaving no place for other people to park.
Every morning when I park in the deck where my office is, I open my door to check and make sure I'm parked straight and evenly between the lines. If not, I back up and move over.
Some people don't have the ability to park between lines as well as other people. That really doesn't mean they deserve to have their car dented and scratched.
I'm glad you brought this up, because hopefully it will give you a chance to think again about your behavior. As another answerer said, it is illegal to purposely destroy or vandalize another person's property. If you get caught, you will be in big trouble. Please think this over.