It's a bald faced lie that pitbulls can't turn it of. Just like the locked jaw myth. They certainly can turn it off, and their jaws do not lock.
As far as owners saying that the dog showed no signs and just snapped..That is simply an attempt to avoid legal liability or responsibility for their animal. It's either that, or the owners REALLY couldn't read dog language and shouldn't have owned a dog to begin with.
Dogs can't lie, as they speak with their bodies. As far as I know, the only breed with a tendency to go crazy for no reason is the cocker spaniel. (Google: rage syndrome)
The problem with statistics, is that it's been proven over and over again that many of the pitbull attacks recorded inevitably came from dogs who do not actually have any pitbull blood. Anything from any kind of bully cross is generally called a pitbull, along with a whole lot of dogs who are not even similar looking.
Even locally, in a small town near here, one of my younger cousins was bitten by a bull mastiff (who had a history of abuse) The police wrote it up as a pitbull attack. :shock:
I'm not saying that there aren't dangerous pitbulls (There are dangerous dogs of every breed. I have a friend who was hospitalized by a golden retriever.), but I honestly do not believe that well bred pitbulls (as in, actual pitbulls, and not just mutts who kind of look like one) are anywhere near as dangerous as some rather questionable "statistics" make them out to be.
My experience has been that they are very eager-to-please dogs. I suspect, had I wanted my dog to kill for me, he would have. Instead, I told him to be gentle to my small animals, and so he was.
I believe that the pitbull problem has a whole lot more to do with a breed (or dogs who kind of look like that breed) being popular with a certain crowd.
Along with opportunistic people wanting to make a quick buck out of selling "pitbull" puppies. Hence, an abnormally high amount of intact males chained in populated areas.
Lets not even talk about people who attempt to "make them mean" on purpose in order to get them to behave as guard dogs. A purpose which they are really not the best breed for, as their natural guarding instincts are fairly low.