Here's a case where the old codgers have a tiny bit of weight on their side because it supposedly was an ice ball. As much as I'm completely on the snowball revellers side, I'm also completely for having completey fair, clean and safe battles.
We only have this one article so don't know the full story but this is extreme. Most of all, a FELONY!?!?!? WTF!?!?!?!?!? This being considered a 'felony offense' in a city that ignores smash and grabs. Get a flipping grip! Even if it turns out that there's more to the story, such as rocks inside, etc., to make this a felony, seems a bit exteme; especially when you consider that the cop car was 'undercover' (UNMARKED).
Now for snowball participants who play dirty, go get 'um! But get 'um with things like, uh, snowballs, scoldings, loitering sorts of tactics, or, at most, a minor fine.
To the snowballers: Please don't be the few bad apples who ruin it for the majority of good spirited folk. Play fair and use a little common sense.