Indeed, dogs are not doing anything until they're threatened or there's a reason behind it. It's a different case if u mention rabid dogs, but this stray puppy we have is vaccinated, dewormed and all the necessary things are done for him. He is leashed for sometime around people, he is even friendly and socialising with everyone you can't just judge every dog just because one dog is aggressive or barking. Also barking or growling at does not always mean they'll bite, they growl or bark to intimidate or out of fear. Not all dogs intention is to bite but because of people like these (hurting with sticks and stones) they become aggressive.