I own a Pitbull, this is my second one and both have been completely adorable and friendly dogs.
They have both been protective when one of the family is being threatened, but not 'aggressive' at all. Dax, my current Pitbull, I will admit is very instinctive and his 'inner animal' comes out when it comes to "game". "Game" being birds, squirrels, possums, etc...but some how Dax knows that dogs, even tiny dogs are not food. He definitely knows that people are not food.
I took Dax to St Eds Park and to Bull Creek (dog park) today. I had one guy comment that he looked like he had been in a few fights. I said, he has never been in a fight or bitten a person or dog in his life. Dax has bad allergies, so bad that his skin has flarred up enough to have left many scars on him. Stupid people assume the worst. Intelligent Pitbull and Boxer owners in the past have recognized his scars and pet him.
Another guy scooped his daughter out of the water when Dax entered the area. I just laughed...thinking from a temperment standpoint the Pitbull traditionally has a much better temperment that the majority of the dogs that were there - specifically the Jack Russell, Border Collie and Weimeraner (back to this one in a moment). If these other dogs had the strength of a Pitbull, Boxer, Doberman, or Rottie they would been know as terrors, they bite people and other digs much more frequently, but they are the worst biters - fear biters. They also simply do not possess the strength or gameness to do the damage that the other breeds have.
Unfortunately, I do shy away from taking Dax out with others because of the general public's ignorance. Anyway, today was great, up until the Weimeraner came along, Dax had been extremely friendly with all the dogs and the people that were nice enough to pet him. The Weimer attacked Dax. No Dax was not threatening in anyway, Dax was not near the owner of the dog or even between the Weimer and the owner. The Weimer bit Dax a couple of times before I intervened a separated them. I was seconds from tossing the Weimer in the water, but his owner finally strolled up to scold him. No apology to me, not even a word...I just said, "And Pitbulls are the bad ones?" Because of this Weimer, I put Dax on his leash for HIS protection.
Rant over and out.