This is so true

 It’s the owner not the breed

The outdated debate, “It’s the owner, not the breed,” has caused the pit bull problem to grow into a 30-year old problem.1 Designed to protect pit bull breeders and owners, the slogan ignores the genetic history of the breed and blames these horrific maulings — inflicted by the pit bulls genetic “hold and shake” bite style — on environmental factors. While environment plays a role in a pit bull’s behaviour, it is genetics that leaves pit bull victims with permanent and disfiguring injuries.

The pit bulls genetic traits are not in dispute. Many appellate courts agree that pit bulls pose a significant danger to society and can be regulated accordingly. Some of the genetic traits courts have identified include: unpredictability of aggression, tenacity (“gameness” the refusal to give up a fight), high pain tolerance and the pit bulls “hold and shake” bite style.  According to forensic medical studies, similar injuries have only been found elsewhere on victims of shark attacks.

Source:   http://www.dogsbite.org/dangerous-dogs-pit-bull-myths.php