The majority of these breed bans have been in direct response to specific incidents involving severe attacks. Fatal dog attacks are rare, however when they do occur the receive a great deal of public attention through the media, and often incite public support for sever consequences. Most people will agree that certain breeds have a propensity for violence towards both people and other dogs. Banning these breeds will obviously cut down on the tragic attacks. What you have to consider is that all dogs are potentially dangerous if they are scared or hurt, so even if specific breeds are banned that does not guarantee that dog attacks will not occur. It is not only the bred of dog, but is size, strength, training, and treatment that often come into play. I have never heard of a Chihuahua or a Bassett Hound killing its owner.
In addition to outright breed bans passed by some local municipalities, many breeds are banned from certain apartment buildings, or housing complexes with HOA rules. A more subtle form of breed bans has recently arisen in the insurance industry, these companies will not insure home owners with certain breeds of dogs. Most of these companies claim that this stems from law suits from dog bites, however many argue that the rise in dog bite law suits is not exclusive to any specific breeds.
