Ah, I see the problem. I'm not refering to guard dogs, I'm refering to protection dogs. There actually is a difference. Guard dogs will bark and carry on, but a protection dog will do something about the situation. A Pit will bark its head off, but if it's human aggressive it is of an unsound temperment for the breed. That's what I meant in my original reply. I have no doubt that people are using Pits for protection purposes, a lot of those same people are going to be very angry with their dog when it allows them to be harmed or licks a burgler to death. The Pit, much like the Rott, suffers greatly from bad and/or unethical breeding. This leads to unpredictable dogs. Too many people put all of their faith into a dog that appears to be protective, only to find out that it's actually fearful or just not as protective as they believed. These cases have been well documented with protection trainers nation wide. Then there's the fact that a 45lbs. dog just won't be anywhere near as effective as a 90lbs. dog in protecting you. And like I said, the mere fact that your dog isn't suspicious and distrusting of strangers means it's not a good protection dog.
This isn't to say that he isn't a great pet and guard dog, but Pit Bulls are not good choices for protection work. That's why the trainer you refered to had to see it for himself. He was shocked because properly bred a Pit isn't supposed to display that level of aggression. Thank you, I try to be as knowledgeable as possible about the animals I own and intend on owning. I've done a tremendous amount of research about this breed and, as I already said, I've had my Rott/Pit mix for eight years so I've a lot of experience with the temperment. If someone is a real threath he'll do something, just like any dog that loves its master, but that doesn't mean he's a good protection dog. From the time that I've spent with both breeds, his actual protective responses are very Rottweiler-like and his social skills are very Pit-like. He likes most people, but is distrusting of a lot of people too. You really do need to spend the time, yourself, reading and learning as much as you can about your dog...you'll both be far more happy.
Here are some quotes and a link for you. Please read this page and the rest of the site, you're going to be very suprised and you owe it to your dog.
"Aggression towards humans should be viewed as a serious fault."
"Because the Pit Bull is generally such a people-friendly breed, they often make poor guards of property. Many specimens of the breed will allow strangers to enter the home or yard without a fuss, whether the owner is present or not. As a guardian of his human, however, the Pit Bull is quite willing and able to intercept an attack. The breed is credited with having exceptional judgement and will react only to real threats. Because of the Pit Bull’s generally poor guarding instincts and natural inclination to protect his owner if need be, it is best to stay away from any sort of guard or protection dog training. A good dog can be ruined quite easily, making for a wary, untrusting animal that may become a danger to humans. Do not try to make the Pit Bull into something he is not. If a serious guard or attack dog is what you desire, it is best to look to one of the breeds that have been specifically created for that type of work."
http://www.realpitbull.com/agg.html