I personally dislike pit bulls, but you will never hear me spreading the hateful propaganda about them. Despite my preferences, there is no denying they are one of the sweetest breeds out there.
We live near a dog park, and pits outnumber every other breed, including mutts, that I see there. They are always very friendly, and my little terriers run off and play with the pits as readily as with any other dog. I suppose an irresponsible pit bull owner would not think of bringing their dog to such a heavily trafficked park. They are bundles of energy and affection, just like any other well cared for dog.
The dogs at the park that cause the most trouble are the small terriers. They can be monsters on short legs . . . the owners seldom seem to think twice about it. I'm assuming it's because terriers are small, and people don't realize they can cause quite a bit of damage. The only truly aggressive dogs I've seen at the park were a golden retriever and a standard poodle. I'm not saying those are bad breeds, they're just not breeds people suspect aggression from, and these two at the park were terrifying.
The point is, every dog has the potential for problems . . . and the potential to be the greatest companion ever. I have yet to meet a pit with even the slightest bit of dog aggression, let alone aggression towards humans.