Written by
Detective Baylor, a 25 year Washington DC police officer is now on desk duty for doing exactly that. During a snowball fight that was organized by a social networking group, Baylor draws his weapon after snowballs hit his personal car. The linked video captures the action and at one point, the crowd beings to chant, "Don't bring a gun to a snowball fight!"
Call me stupid, but I think it would be the other way around and if the cop actually flipped out and fired off some heat, you better be packing more then ice.