I guess I'm not advocating either way, but I have been on both sides of the story. I've got two stories to relate. My dog has never bitten anyone, nor has she made an attempt or growled. (The neighbor kids actually ask if she can come out to play in the summer). She barely ever even barks, but that is because the breed was originally developed in the Bordeaux region of France as a silent tracking, hunting, and guard dog. Just to be clear, my dog is a Dogue De Bordeaux (AKA French Mastiff). She is nearly 6 years old, and I have had her since she was 10 weeks. I remember the first (and last) time that I brought her into a big name pet supply store, to have her nails ground and pick up some dog food. The younger gal behind the counter (probably about my age at the time), asked me what breed she was, I told her, and she told me that my dog was illegal in (X) city. I of course, did some research, and contacted the local PD. Nothing on record of her breed being illegal. I, of course, went back to said store (with my dog), and made sure to give them the correct information, along with the police departments contact information.
Another story involves an attack on a friend with another friends pit bull (unfortunately) a couple summers ago. This dog had been brought up in a ROUGH environment, and had been re-homed (which is where the friend who owned it comes in). I was on his patio, with his dog, and a female friend. The female friend, of course, was petting the dog on the head, while facing him. As girls do she leaned in to kiss the dog on the top of the head, and the dog snapped. Nearly took her bottom lip off and split her top lip clear in half before I could get my hands on the dog. Automatically (as fast as I could), I grabbed the dog and isolated it in another room. I rushed the young woman to the hospital, and thankfully after surgery, she has minimal scarring. This was not the first incident with the dog, and the dog was immediately euthanized.
I am personally a believer in how the animal is brought up. With that said, you should still keep in mind that an animal is just that - an ANIMAL. Just because they are X years old and have never bitten anyone doesn't mean they won't. Also keep in mind, humans have animal instincts too - and animals can read those. If you show fear, animals will take advantage and show dominance. Always expect the unexpected, and the only thing to fear is fear itself.