[Back in Black]

It's a specific training technique which results in them not trusting anyone but their owner to feed them. it's part of making them into suspicious watchdogs as well. Try to feed them or toss meat at them, and they will get very angry with you. My home has never been broken into, although one night in Sacramento, CA., as my buddy Boris Von Blitzkreiger (Rottweiler) and I were snoozing, me on the couch, him on the floor under me, trying to guard the front door as the house cooled off, a punk tried the screen door. He figured the yuppies in there would not notice the missing stereo/TV etc. until 8 AM ...At the sound of my magnum cocking, (I awoke from a nice sleep with it in my hand, cocked, pointed at his belly 15 feet away) he stopped dead, his hand on the screen door handle.. then Boris woke up, roared and slammed into the screen door, denting it. I threw open the door and sent him out like a locked on missle after the creep... The punk got away... he must have melted his tennis shoes and left a brown streak down his pants and the sidewalk...
Just having a dog is not having a guard dog. Most dogs are socialized and are simply bred and raised to be pets. They bark but cannot protect, and are simply alarm dogs to wake you if you are home and someone is breaking in. Some will sleep right thru that too, and maybe even hold the flashlight for Mr Burgler
On the other hand, most people are not responsible enough to have/deal with the liability of a guard dog.