I have aggressive (I would even go as far as to say unstable and vicious) dogs in my neighborhood. I don't have a massive dog to walk with that will defend itself and me from them. I will spray/hit/kick/throw rocks at these dogs every time they approach me. If I greet them with friendliness, they attack me (not just barking and growling, but lunging and charging). They will run after me to attack my dog. In fact, the only dogs they won't mess with are the other two dogs that live with me, who are fiercely protective of our property and would fight to the death with these intruders.
These are not small, harmless dogs, they're Rottweilers. I will NOT adjust my lifestile to suit these ill-behaved animals. I understand that this is a semi-rural neighborhood and some people like to let their dogs run loose, but aggressive dogs with a tendency to roam should not be allowed outside their yards without a leash, ever. I will defend myself and my dogs, even if it means inflicting pain on these dogs.
I get along quite well with every other dog in the neighborhood. All of them have gotten loose at some point and I know most by name. If I encounter them on my walks they'll often join us. If I see a "new" dog approaching us, I put my dog in a sit-stay and greet the dog first. If it's friendly, I leave it alone. If it's super-annoyingly friendly, I shoo it off.
I generally do give dogs a chance, don't think I go around beating up loose dogs. I just won't take chances with dogs that act aggressive, and the "bluffers" are no exception. If a dog feels the need to follow me on my walks, barking and growling, I will scare it off. If it can't be scared off, I'll spray it or chuck a small rock at it. I don't need stray dogs harrassing me.
I know it sounds like I really am not much of a dog lover... LOL. I am, but I don't have much tolerance for loose dogs that display aggression when they are off their territory. I don't subject my neighbors to MY barking/growling dog harrassing them on their walks, and I shouldn't be subjected to theirs.