He is doing what he should be doing and that is guarding your place. Your kids and all. If he is that protective then I don't think anyone would try to kidnap your kids from the yard. That would be a good thing. I have a boxer that I know would bite if someone came in his yard. It is his place and he protects it. Not even the water people can check the metor if he is out. I have to keep him in on the days they check or they won't check it. If he is in his yard then I think that is the persons fault that he bit. If you have beware of dog signs then that should let people know to stay away from the fence if they don't want bit. I am glad my dog protects his yard and us.
Chris
Chris