My nephew woke up with a drunk woman sleeping on his couch.
First he saw a pair of dirty work boots by the back door. His german shepard,Oats,was laying on the floor beside her. Oats and a fence is the reason he doesn't lock the door. Oats goes nuts when anyone gets near a gate. The nephew told her to leave and she did.
He logged onto his security system online,watched the video of the girl stumbling in at 5 AM,motion detectors had kicked in. He also found out he has to click on an icon,so now they will phone him when the detectors turn on.
"Boy you're useless,hey Oats" he said,affectionately,as we talked on the phone to me. "Oh yes you are"
= new reply since forum marked as read
Dogs:
those with instincts to guard property, and those that guard humans.
German shepherds are know for being very protective of humans, and a bit more mellow about property (unless they're trained otherwise).
I'd think, if the drunk girl had approached your nephew or his son, Oats might've behaved differently. 
Some dogs will go bonkers if someone tries to break into the house, but if you're attacked in your front yard, they don't really get upset. With German shepherds, it's usually the other way around.
