Same thing happens on my street sometimes its not possible for me to park my cars outside my house so have to leave it nearby in front of others. Its always people who haven't got a car and are jealous that complain luckily the person causing the bother moved last week so I am in luck. But for me i couldn't hold my anger in if someone keyed my car in my street so probably return the favor but would regret it in the long run since they probably wont go away.