They wouldn't get bitten very often, if ever. Most dogs see someone new and think, "Oh Boy! A new friend!"
I did door-to-door sales for a year, and met hundreds of dogs. A couple were aggressive, and I just backed off. The rest were all friendly, looking to be pet.
Even the ones that put on a show aren't going to bite. It takes a rare type of dog willing to seriously engage a hostile person. Its exceedingly rare in your average pet. The dog that puts up a big bark and show is not different than the punk at a local bar that puffs up and talks a lot of shit... both fold when the rubber hits the road.
I'm sure you've seen what I mean going door to door. I train dogs for protection work, and breed working line shepherds so I have very unique insight into this particular subject matter... that being when it comes to dogs doing violence upon people ;-)