I have a protective bulldog too (not an American pitbull terrier, Staffordshire terrier, no terrier blood) and I have signs on the gates, the front door, and the gates are all locked since the time the lawn spray guy left a gate open.
One day I heard a ruckus and went to the front door and he was hanging on to the mail lady’s arm. It was snowing and she had cracked the door to slide in a package.
He didn’t bite her. She was wearing a thick winter coat, no bruises, no broken skin. He thought she was an intruder and was holding her there until I told him it was OK to let her go. I didn’t train him to do that.
In any event I would rather he were pepper-sprayed than shot. If someone points a gun at him, I have a gun too. The US post office won’t bring packages to my door now and that’s fine with me. The census guys, Jehovah’s Witnesses, Girl Scouts and salesmen—all the Ding Dongs—they can leave whatever they want me to see in the newspaper box.
Ummmmmm, OK, if you say so.