I'm no fan of dogs as a general rule. To me they're way too needy in the attention department. But I once owned a Pit Bull Terrier who was the most endearing dog I've ever met. He was loyal and protective to a fault. but he was very smart and perceptive. He knew who was supposed to be in my yard and who wasn't. At the time I lived with my older sister and her three boys (they were ages 18 mos, 2 and 4 at the time) They played with him and their dog (a stray we found as a puppy who is definitely more than half coyote) They would climb on him, bounce on his back, pull his ears and tail, and dump dirt on his head. He just laid there and took it, his only reaction was an occasional kiss and wag of the tail. He loved playing with them and always got excited when it was play time. He's the only dog my family ever owned they understood that he couldn't jump up on a small child no matter how excited he was because it would hurt them. Unfortunately, he was very smart and easily escaped my sister's yard on a daily basis. The neighbor's were none too pleased. And even though many neighborhood dogs roamed the streets with no complaints, they complained about him. Based mostly on the perception of pit bulls as violent animals. One particular neighbor claimed he bit her, but never showed us a wound or even tried to press charges (criminal or civil) so I highly doubt it. Nobody ever complained about the other dog getting out, even though it's obvious he's more coyote than dog. They weren't scared of him, despite the fact that coyotes have been known to pull small children out their own back yards.
I got my Pit as a puppy. City ordinances where I lived void your home owners insurance for owning any variety of Pit Bull, so on his first vet visit, we had his breed registered as 'some type of Great Dane mix, we don't know for sure because the guy we got him from said he didn't know either' the vet obviously didn't believe us, but put that down anyway.
My dad is a huge fan of dogs so we've owned quite a few throughout my childhood. When I was younger, he bred and trained watch dogs, and I spent much of my early childhood surrounded by Pits Bulls, Rottweilers and Dobermans. I played with them all the time. Even dogs that were going to used as 'junk yard dogs'. My dad never restricted my playing with them. I've only ever seen one dog in my entire life suddenly 'turn vicious'. That was the only Chow we've ever owned. He growled at and bit my older brother when he was feeding him and then a few months later bit a neighbor kid while we were playing in our yard. My dad had the dog put down after that. I know the people down the road from me owned a Chow that was extremely mean. To the point where my mother wouldn't allow us to walk down the road in that direction, and the owners of the house left him there when they moved. I always felt sorry for that dog though, he didn't have ideal owners and I think that was his biggest problem. I've heard more horror stories of German Shepherds turning violent than any other animal. The wife of one of my dad's friends refuses to enter his yard unless his German Shepherd is restrained because she witnessed a German Shepherd literally eat the face off of her cousin when they were children. My sister's mother-in-law owns a German Shepherd who growls and snaps at everyone, even family members, and actually bit one of my nephews before he was even 2 years old. Why aren't more people afraid of German Shepherds?? Because usually it's not the breed, it's the dog and it's the owner. My sister's mother-in-law has never disciplined her dog for anything more than pooping on the carpet, even after if bit her toddler grandson.
I read comments from people who think all Pits are violent because of certain past experiences. I once saw my dad's half Pyrenees half Lab violently tear apart a chicken, and a rabbit. And I was once attacked, totally unprovoked, by a Labrador owned by my pastor when I was 11 years old (this dog was always mean though, and was well known for it in our church, she didn't just suddenly decide to attack me against her nature). Does this mean I think all Labs or Pyrenees are violent animals that one shouldn't be allowed to own? Not hardly. It doesn't even mean that I think my pastor is a bad person for owning a mean dog. She was a rescue dog, and really it showed his compassion that he wanted to try to work with her and make her better. My past experience with Chows doesn't really effect my opinions of them either, even though most breeders and trainers will warn you that it's in a Chow's nature to get meaner as it ages.
Dogs don't have the reputation of being 'man's best friend' for nothing. Dogs may be bred for many different purposes, from hunting, to herding, as service animals, and as guards, and each breed has characteristics specific to it's purpose. However. one quality that is never bred out of dogs is their loyalty, their friendliness and playfulness. Breeders take great pains to maintain these qualities. Any dog can turn vicious through being neglected and abused, or through training. Unfortunately, the dogs with the reputation for being vicious are bred for strength, speed and intelligence and as such are trained by certain people to fight. This just completes the constant circle and reinforces stereotypes. But any type of dog can be made violent, from a Teacup Poodle to a Bull Mastiff, if it is raised to be that way.