This kind of thing really pisses me off, it's so pointless, and now all these folks have to go through the trouble of getting their insurance to pay for it and get it cleaned off or repainted.
This area seems to be a hotbed of vandalism too, there have been a number of car fires near 13th and Otis, plus at 11th and Park.
The reader said he reported the incident to the police, which is something you should ALWAYS do, even if you don't think the police will come or will catch the person. If they have a report on it, it can at least add to their statistics and allow them to see patterns and do other kinds of analysis.
Hope this sort of thing doesn't happen again.