Of course the news reports on the cases of strangers.
This is part of the problem -- we're all so interconnected and hear so much about horrible things that happen that we start to believe they're commonplace. It's difficult to maintain a sense of perspective.
Perspective:
There are approximately 70 million children living within the United States today.
Approximately 3.5 million cases of abuse were investigated in 2007.
Assuming that all cases were legitimate, that's 1 in 20, or 5%. This includes all cases of abuse, be they physical, sexual or emotional.
80% of those cases were perpetrated by one or both parents. The overwhelming majority of the remaining cases were perpetrated by someone known to the victim (a caregiver, family member, neighbour).
Pretty pretty picture:
Further reading.
Child abuse is a terrible thing, and it's important to protect your children from it. However, it's equally important to remember that these things are relatively rare in happy homes. I'm not going to tell you not to worry about it, or even that you shouldn't. It's something to keep in the back of your head, but make sure that you remember to let your little girls be little girls too. That includes things like playing outside, scraping knees and doing all the assorted things that kids do.
I Am Not A Parent. It probably shows.