I asked a mailman about this once and he said he carried dog biscuits with him and he only had a problem one time, with one dog, after that.

It is bizarre though, our Weimeriner, Cadet, once attacked a police officer that came into the house. This is the same dog that would have shown the burglars where the valuables were. The cop even came in the door with me so the dog knew he was ok, but attacked him. I think it's the uniform. I think dogs remember the holocaust.

It is the uniform. My dog, who is normally a mobile footwarmer, went balistic when uniformed painters attacked our neighbor's house.

On a related note, shamefull as it may be, my brothers dog is racist. Meaning, he gets agressive against other colored people.

This is not learned however, and I do think alot of dogs suffer from this trait.