Whatever it is, it needs some standard behavior training, and badly. Dog like that, not controllable by voice, can be a hazard to everyone around it, no matter how benign it's temperament. The size alone is a bit scary.
One of my favorite sites to read at to pass 10 minutes or so. The lists are written and submitted by folks that frequent the site, and sometimes they’re full of errors and wrong info. They had a list about pit bulls the other day. My kids’ mom has one mixed with boxer we think, he’s a sweetheart.