Whens the last time you heard of a Chihuahua attacking or killing a child or an adult? Not sure why you associate a thug with a pit bull. I've known good, decent people that owned pits, they just didn't use any common sense by having a pit in the first place. jmho
----------------------
C'mon semi. I'm pretty sure you're smarter than that. 
Tell me then....How many YoMos have you ever seen walking a Chihuahua down the street on a spiked collar and a choke chain?
Not many-if any. That's because Chihuahuas aren't badass-looking like Pitbulls.
Google is your friend:
It's not the breed that's bad-It's the stupid owners.
Road Puppy,
I respectfully disagree as the breed has been bread to be violent and to attack. Other breeds have been bred to enhance things like retrieving etc. and while even untrained they have the instinct to do what has been bred into them. That is the problem with pits as in the case I spoke about good family pet never fought or abused snaps and almost kills a 6'3" 230 lb man. They have been bred to be killers. While you are right it's not really the dogs fault you never know when the breeding is going to come out and the dog follows what has been bred into it. It is sort of like asking my dog not to chase a squirrel sometimes he can control his impulse "breeding" sometimes he cannot.
Yes other dogs bite and attack but there are only very few breeds that can kill a human and one of those breeds "pits" far exceeds the others in fatal attacks.