Something doesn't seem right about Doctorow's example of attacks on children. He writes, "But the fact is that attacks by strangers are so rare as to be practically nonexistent. If your child is assaulted, the perpetrator is almost certainly a relative (most likely a parent)."

I'm sure that's true, but it doesn't answer the real question. For most parents, the question is: given my child's particular environment, what is the greatest threat to him?

Doctorow is saying: given that your child was attacked (and no additional information), the attacker is more likely than not to be a relative. That seems backwards.