The problem with powerful dogs like these is, when they get angry, as any dog does on occasion, they can do serious damage. Then, some breeds are bred to be especially aggressive, although it’s clear that, if properly trained and cared for, they can still make excellent house pets.
And don't forget luck. If you have an aggressive breed you need some luck. Even in the best homes with good training, they snap, someone is hurt or dies. Stay away from the obvious aggressive breeds.