Hillybilly Santa Claus, paraphrased wrote:
If he hits his sister, he'd get ten to fifteen licks with a rod. That's to teach him that violence in society is unacceptable.
I don't believe that spanking for really foul behavior is a bad thing, but not to that extreme. He's right in that violence is unacceptable, but trying to enforce it with far more violent behavior is just the wrong way to go about it.
I've been pretty lucky, in that my little girl isn't demonic. She'll throw the occasional temper tantrum if she doesn't get what she wants, but she's two. Kind of expect that kind of behavior. Rarely lasts more than four minutes. She's misbehaved once or twice, and I've spanked her for it though. These people needed freakin' moderation.