I usually avoid houses where I know there are aggressive dogs loose. Otherwise I stand in front of Autumn and keep her leash loose and tell her to sit until the owner comes to get the dog, if no owner I've been known to take them to the shelter. I'm lucky in the fact that Autumn is an excellent judge in character. She knows if other dogs are going to be agressive or not and acts accordingly. I've found that if you hold your dog's leash tight it seems like they are trying to dominate the other dog because their head is held up. I agree that you should do something about the leash laws in your area or write to the owners.