I agree with SRS and Richard that it is the negligence of people to properly train and supervise their dogs that is the problem. Many people forget that dogs are animals and will often revert to animal behaviour in situations of unfamiliarity, such as being exposed to children if they have not been socialized to them. A dog who is not used to children and their often unpredictable movements does not perceive them as people and may feel that they are a threat and will react defensively. There are too many dog owners who are ignorant of the basic knowledge of animal behaviour and these people are irresponsible.