My points and I'm out:
I don't key cars that double park nor do I do anything to them for that matter.
I think keying is too severe too... I like the idea of letting the air out of a couple of tires. Only aggravation, no permanent damage. Karma if you will.
I'm fine with cars that park away from everyone else - that's the proper way to do it if your car is that important to you.
The reason cars get keyed is because it's human nature for people get pissed off when they see someone taking up 2 spaces when everyone else is following the rules and respecting their fellow man. Absence of this respect = chaos.
It's really simple if you don't want your car keyed in a parking lot - just don't take up 2 spots. Like everyone else in the parking lot doesn't. That's how societies work.
Regardless of how you feel about retribution to these thoughtless people, you benefit because it happens.
If you think about the logical progression if everyone could double park without concern for their car's well being, you can figure out where it would lead.
Bottom line:
People that randomly key cars = Tool and criminal
People that key double parked cars = complex situation as this thread attests, but bottom line for me is that I think the driver deserved it for selfishly putting their interests above everyone elses, and that if it didn't happen we'd be overrun by these tools. I'd vote for letting the air out of their tires, but since keying is quick and simple that's why it happens.
As a last comment, I'll bet that a lot of people who have keyed double parked cars are normal ordinary people who have never done anything like that before and likely never will again.
Here's to no door dings for anyone