"They're so sweet with my kids...." Better hope they like *ALL* kids as well as his.
First of all, let me make this perfectly, crystal clear: I DETEST DOGS. I'm terrified of them, all of them, from big dobermans to little poodles. And it wasn't that way until I got bit by one as a little kid. Not severely bitten - but bitten.
Since then, I've been around several dogs, because Skander and his wife have several and have fostered others through an organization called "Second Chance," my brother has had various dogs - INCLUDING PIT BULLS. Now, he's got two German Shepard puppies. And yes, I'm terrified of them, despite the most positive dog memory I have is of a German Shepard that came to our house before I developed my fear of dogs. It was friendly, and my brother and I grew really attached to it in a very short time. (Dad listed the found dog in the newspaper or something, and the owner came and claimed it. And yes, it was the real owner. Broke my brother's heart.)
No one should ever think that a dog is a "safe" animal - even if it is gentle towards some, and especially not if there are kids in the house. There's a "pack" mentality in dogs, and a position of dominance will be sought; it's in the animal's nature. If there's a weak target, regardless of reason, it'll seek to establish dominance. This isn't the kind of animal that should be kept as a pet!
Pit Bulls are just like any other dog in this behavior. And the ones that survive, generation by generation, are the ones that are more aggressive, establish dominance, etc.
If you want a pet, get a cat. Oh, don't get me wrong - they're dangerous in their own ways, and care has to be taken with them around infants, as well. But you're not going to hear of the upset cat that killed the 7-year-old from down the street. Won't happen - unless you're talking about something like this:
http://www.musicsrc.com/video/BRUTAL+CAT+ATTACKS,+FATAL+INJURYS.php?id=9SmISPp7ENMCats are the way to go. Much safer. Much more graceful and elegant. Much cooler animals and much better pets.