I think pitbulls just attract douche bag owners and that compounds the problem
		
		
	 
Cool thread, I wanted to weigh in and provide yet another opinion that in the end doesn't matter to anyone but me.
I believe the nature vs. nurture is a mix of both, however I truly believe that only in the absolutely minority worst of cases can bad behavior not be trained out. I am talking about dogs so inherently mean that there is no saving them. Otherwise I truly believe with enough time and effort you can make any breed into a "good" dog. To go with this idea, I do believe even the "best" dog can snap for whatever reason and try to kill someone, unfortunately this is just nature. Maybe it's not that different from humans?
I have met a few very nice and loving, obedient pit bulls. The friends that own them absolutely love and adore them and I have never once seen any sort of hesitation when they come to greet new people at the door. Here is where I wanted to put a personal spin on this discussion. I have a 6 year old black lab, Brooke. She is absolutely adorable, I will be any amount of money that she will take more love and pets than you can give - as in I will be you she will sit there and not leave your side and bug you for more until you get tired (if I don't tell her to go away, she is a very obedient and intelligent dog). The caveat to this is that she will probably not like you for the first 5 minutes. She has a mean mean bark, she will growl at you, if you go to pet her she will snap in the air (never at anyone, never bit anyone, pure defensive posturing). After the first 5 minutes of you sitting on my couch you will have a new friend for life (well she may forget you once or twice but never after the third time). If you want to pet her over the fence or through a car window... absolutely no chance, again her bark is very scary. She is 6 years old and I still have to puppy proof the house because she gets bad separation anxiety, she is so extremely protective of her house and her "family" that unfortunately these are the tick's that I have to work around with her.
Key word, 
I have to work around it. It is my responsibility to inform people that "she is a friendly dog but please don't pay attention to her for the first 5 minutes, and please do not stick your hand out to pet her because she will snap in the air". I tell everyone this, I will say that probably 20% (conservatively now that I think more about it) think they are the flipping dog whisperer and that rule doesn't apply to them. I have to be the firm one with them saying "I know you are good and comfortable with dogs, but please for my sake and out of respect just do it my way". A dog is a liability, even if I warned the person, and the person got their hand too close to the dogs mouth while she air-snapped, I am liable, period. If the wrong pizza delivery driver wants to be a hero, my dog breaks skin, and now (God forbid) they want the dog to be put down, you know how awful that would be if you just knew that after the first 5 minutes she will love you to death? Honestly she would not harm a fly, even her air snapping is with her head back and held to the side, she only goes near you to figure out who you are.
I know there are things I can do to help work on that behavior (I don't overly feel the need to yet), and I also know the behavior is in small part my fault (only due to me being the owner and in the end I should have final say) but a large amount of the blame for her behavior I put on other people. I have a very social household, and this dog gets spoiled by everyone other than me. My girlfriend, amazing person, terribly terribly over caudles the dog, gets way too excited and happy to see her right when she walks in the door, and lets her break rules more than I would like. When friends and family come over they don't care that I don't like feeding the dog scraps, or that I don't allow her on the furniture, or that when I say "enough is enough, Brooke go to bed" they always say "no no its okay I love Brooke" when she gets all hyper and happy when greeting them, not realizing that it is my dog and I am allowed to have a certain expectation of how I want her to behave, which is ideally to greet people for a minute but when I say go away to go away. The reason for a dog to be obedient is not to show how smart they are or that they can do it, it's so when your dog sees a 4 year old kid that it just wants to say hi to and runs towards it (knocking it over or smoking it with her hard head) you can simply say "Come" a single time and never worry about it. My dog will do this for me 95% of the time, my girlfriend maybe 70% at best, and it is easier for other people to persuade her out of it. Other people are the worst for de-training your dog, and my family calls me the biggest hard-ass with how firm I am with her, but I have to be because I love her and I don't have a million dollars to pay if her clumsy lab self hurts someone.
I quoted the above posted because I think that dogs pick up on the personalities of the owners a lot. I agree 100% all these ghetto tough guys want pit bulls for street cred, don't take the necessary time to train them properly, and then there are issues. I have never once been worried about my friends well trained pit bulls, more than I would be about any other big dog I mean. Now I am not generalizing and saying all these attacks are happening by owners that are completely useless, I recognize that sometimes it just happens. In the end I think there is a reason it happens more with this breed, I think when you break it down to odds, in this particular breed it is just a) harder to train them properly and b) more inherent to their nature to attack (just a little bit). I think when you look at the odds you need more perfection out of training and a little more luck with the dog itself than you would with a standard lab lets say. Yes if a ghetto thug raised a lab you be there is a greater chance of violence than with a regular owner, but I think due to the nature of the dog though there is a lower probability of it (if even a little bit) than it would be of a pit bull with the same owner. However I do think that if you put that same pit bull in the hands of a competent owner and trainer (before it is too late I mean, cuz sometimes it is IMO) then that same dog has a far far greater chance of being an amazing dog.
Jesus I didn't mean to write such a long post, sorry guys. Good thread though, a lot of good points in here.