"Vicious dog on the loose!"

I was just getting out of the car, and this guy ran past me with his dog--not using a leash--and yelled out, "Vicious dog on the loose!" somehow believing this to be funny. Why are people so convinced that everyone else finds their dogs as nonthreatening as they, the owners, do? Dogs are machines biologically programmed to kill.

Almost nothing angers me more than dog owners who let their animals run around outside without a leash. Well, nothing that you see in ordinary life, that is. There should be some kind of a dog owner's license, one that can be taken away after such behavior. These people would put their dogs on leashes pretty quickly if they thought their dogs could be taken away from them (as well they should be).