Or, it could have been parked entirely correctly minding it's own business and then some jealous, unthinking, mindless piece of crap decides "oh, i can't afford one of them, and my dogshit mind won't allow me to think of a way to get one myself, nah, i'll just damage this one, doesn't matter, i didn't pay for it, f**k em all"
Some people need a good keying I reckon. It's happened to me a few times and I'm still very bitter about it...if I EVER catch someone damaging my property theres going to be trouble lol
In fact, if I saw someone elses car getting damaged, it would cross my mind to introduce the perpetrator's head to my foot a couple of times