One thing Sue left out is the Locking jaw,Yes!Pitbulls have Locking Jaws,& when they are puppies like any other puppy,tug o'war is a very popular game to play with any pup,however pitbulls learn early that they have the lock jaws,& If the owner trains their dog to attack,that locking jaw will be utilized,Each & Everytime.Now factor in the bloodlines,& you have a potential 4-legged Killer! They are short statured dogs,so if they do attack another dog,especially larger than themselves,they will home in on anything at their level,usually the throat & stomach,then they shake their heads back & forth till it rips/shreds,they then bite deeper till the threat is neutralized.Ex-cons have these dogs,as it is against the law for them to own certain Knives & All Firearms,there are many ex-cons so there are many of these dogs with the same mindset as their owners,not to mention the scumbags that raise them for the sole purpose to fight other dogs.I had a Pitbull for 16 yrs,I'm proud to say he was family!