I consider the "mob" a deadly weapon in itself. A mob of punks wish to do nothing more than cause damage, harm, and mayhem, and force must be stopped with force. At the first glance of a gun I think they would ALL get scared and run, and those that don't are stupid and deserve to be shot, or at the very least, lose a knee-cap!
Sure, a couple will have the g'nads to stand there and DARE you to shoot them, and in that case, let 'em have it! I'd rather be judged by twelve, than carried by six!