Bad parents...or bad government
It's a classic witch-hunt story...only in this case they really did think they were pursuing witches. I don't take much comfort in the fact that this kind of behavior seems to be built into our psyches, since it occurs at somewhat regular intervals in various different countries and cultures.
I guess the scariest part is that I don't really know where I stand on the whole government versus parents power struggle. As a parent, my instinct is always to say, "Stay the hell out of my parenting decisions." On the other hand, you only need a few horrific tales of children abused to death to swing the pendulum the other way. That fact is, there are a lot of horrific parents out there, as well as horrific government officials. Either you opt for a lot of innocent parents to ruthlessly prosecuted, or you opt for a lot of innocent children to be destroyed by abuse. And the point of optimization between these two extremes is not easily found.
In such impossible cases, my philosophy would default to interfering the least. "First do no harm" should be the adage of government as well as doctors. And while I find myself constantly saying, "Some people just shouldn't be allowed to have kids," I don't feel like giving anyone the power to decide such things for others.