My dog hasn't, but it doesn't mean he won't.
I tell people that he hasn't bitten in the past, but it doesn't mean that he won't. I just don't know for sure. He has had some behaviors such as growling and snapping (at the vet tech when she drew blood), so I know he's capable of it.
That being said, people can just be so darn DUMB. Once, I made the mistake of taking Max to the St. Patrick's day parade. He got really stressed when walked..all the legs. I think he was afraid he would be stepped on. I took him back near a building and set him up on a large planter out of the way so he could calm down. People would come up to him and try to pet him..even after I told them not to. Parents too, were trying to have their kids pet him even though he was growling at anyone who put their hands near him. I just can't stand the stupidity of people. ( And yes, I was stupid too..I thought he would enjoy all the people around..he loves people.)