This has been posted probably 50 times over the last 10 pages, but any breed of dog can make a great, loving pet, or be completely vicious and unpredictable. Some breeds, such as Pit Bulls, Rottweillers, Dobermans, etc. have a stronger tendency than others to attack, and are more capable of inflicting damage than other breeds, although any dog can be vicious. In most cases, the main influences on a dog's personality are the inborn characteristics of the specific dog, and the owner's treatment of the dog. I have seen pit bulls and rottweillers that were excellent, friendly pets (heck, I even played a game of "tug of war" with one or two, and still have all my fingers), and I've also heard of a Golden Retriever (our last dog, who died when I was 3 years old or something like that) that could be vicious and attack people on occasion. That dog was never abused or mistreated, and was still a vicious dog.