Most of the pit's you have heard about are "hood bred" pitts
. you can take a chance and get a random pit catch dog from some unheard of guy and yes he does have a chance that he could be aggressive, hell
ALL dogs can be aggressive. its not so much the pit as it is the breeder. some dogs are bred to fight but i have also seen a couple well bred mannered pitbulls that you could tackle and punch in the face and they would just sit there. a pit has just as much chance of turning on you than a bulldog, staghound, or a chihuahua
