Shepherds get it too. Any pointy eared dog with longish hair gets called a shepherd even if it's a mutt.
My point is, you are up in arms about a dog being called a pit bull, but there is no evidence that the dog was NOT one of the breeds people call a pit bull. Whether it was a cross or not, if it looks like what people call a pit bull, that's how they are going to classify it. I bet even the owner doesn't know exactly what type of breed or mix of breeds the dog is- she's going to call it a pit bull too. Unfortunately, there are few people who can distinguish between the breeds, so if someone's staffie or amstaff gets called a pit bull, there isn't much you can do about it. It's the thug mentality that has brought down all these breeds and it will take a long time for that stigma to change. But writing a letter to the press over them calling a pitbull type dog a pitbull, isn't going to change much. I understand your frustration and anger, but I'm not sure if your energy spent on this incident is going to do much good aside from frustrating you more.