Any dog can be dangerous if threatened, no matter how nice it is. You should never pet an unfamiliar dog on it's head or in any way make yourself be above the dog, as this is interpreted as aggression. Also, never touch the dog's food whilst it is eating. n_n
I had one for 17 years and she was gentle, loyal and smart. All dogs need consistent training by their owner and unfamiliar people need to know how to approach dogs. My dog was eating out of a bowl and a woman came up, on a camping trip, and allowed her toddler to pet the dog. This is the only time I ever saw the dog snap or be possessive of her food. The woman should have known better and I even told her to wait till my dog was done eating!
My golden was a wild, crazy, amazing dog. He let anyone pet him, was great with kids, would protect your life, and was very gentle. One time when I was little, I handed him food in my hand. He gently pulled it out without even scratching me. Best breed possible!