My husband and his family used to train police dogs (mainly GSDs) for the Travis County Constables, along with other states, before his dad passed away a couple years ago. I got my girl GS from there when she was about 3 months old. The last 6 years she has been my shadow, my protector in a few different situations, but most of all my best friend. I did some basic training with her mainly obedience, some agility. Once your new addition bonds with you, no one will be able to come near the house. That's now THEIR house lol. My mother in law still has my dogs litter brother, and his son. I can't come near their house without setting them off. Even walking in, the younger one still stands between my mother in law and me, guarding her. The brother, well, he's plopping his butt on my feet until I decide to move lol. My girl will give a warning bark at the door when someone knocks. Then she comes and stares at me grunting until I acknowledge the door or her. Then she will wedge herself between me and the person. With my 3 year old niece, she herds her to stay near the couch, but if she wanders off, she will stick to her like glue. If you walk in with a hat, or sunglasses on, you will be inspected for a much longer period of time, than if you came in as yourself. One thing, don't ever tell a stranger your dogs name. If for some reason they break in, they have the ability to call your dog off...his name. If you have any questions, I would love to help. Just give me a shout.