I'm interested in what you think a protection dog should do.
I'm not an expert in this field, but I'm risk-averse. I have dogs but they are pets, and they are mutts. Over 50 pounds each and protective and VERY barky around anyone who isn't my wife and myself. I think they would dissuade anyone from breaking into our house to be honest, even if they aren't trained to attack people. It's the noise factor.
I'm also concerned with labels. A 'protection dog' is, to my way of thinking, a liability. If you have a dog that you've purchased and trained specifically for that purpose and it bites someone, that's something that any good attorney for the person bitten is going to use against you. Same thing signs warning of 'guard dogs' or 'attack dogs' or even 'beware of dog'. My dogs are pets. They are not intended to harm anyone; if someone breaks into my home and gets hurt, well, that's on them, dogs will bite when threatened.
I love dogs and I think dogs are great at protecting people, that's not my point. Just interested in the potential liabilities in our increasingly litigious society.