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 ;-)