That is exactly what I first though. I won't even park my car in my parking lot where it's dark, much less take it into downtown and leave it out of my sight. No way, no how.

Personally, had it been me, I'd have waited for the cops to show up and make sure those kids knew exactly what sort of crap they were wallowing in. Though that would have a downside too - had they been malicious they would have come back next time they saw my car and damaged it. It's a fine line. I think calling the cops on them was a good move though. Those kids are in the gutter already, and like a PP said - I doubt they have a father figure at home, or at least not a decent one.