Fuck this same shit happened to my parents. They're super animal activist resecuer types. They rescued a baby kitten a few months back, and my mom was in the front yard of their house gardening, and had let the kitten outside to play (she wasn't allowed out without supervision). A couple was walking their dogs off their leashes, and the dogs immediately ran into my parents' yard chasing their cats. My mom got in between one of the dogs, but the other one went around the side of a car where she couldn't see it. My mom was so pissed, and the couples' exact statement to her was, "It's just what dogs do."
My mom found the kitten about 30 minutes later, she had made it back inside, but the dog had done serious damage to her. She had crawled under my parents' bed and was dying, and terrified. $2000 in vet work couldn't save her. My dad was more angry then I think I've ever seen him. He's the kind of person that understands dogs are just dogs, and wouldn't hurt them. The people walking the dogs, however, are in severe danger if they walk down that street again.