as a 10yr old kid I was attacked by my best mate's guard dog
my mate was inside and I showed up at his house, but the dog got me before he knew I was there. It leapt up and bit my face, knocking me to the ground. It then bit my head and neck repeatedly. the dog was an argentinian dago and it would have killed me if I hadnt yelled so my mate came outside and called it off. I still have a few scars on my head 10yrs later.
It was a wonderfully bahaved dog and stopped instantly when told to, but when no one was there to tell it to stop, it wasnt going to.
The problem with a dog trained to attack people is that you cant be with it 24/7, and if a friend comes by without you realising, or without you being there, then the s**t could hit the fan in a very bad way, it almost did with me, even though I had met the dog 100 times before, it had never been without my mate there (or his sister )