Bright Lines

In a post about parental whuspping of unruly kids, Simple Justice says

What is not at all clear is how to develop a rule for parents to understand where the line is drawn between good and responsible parenting and child abuse. Do we want to leave it up to the nearest Schandelmeier-Bartels, making the determination of whether one happens to have a zealot close at hand to call the cops any time a parent behaves in a way in which she disapproves? But then, we are also aware of many instances of serious child abuse by parents, resulting in death and disability of children that leaves us asking how this could happen without anyone intervening.

and asks

Where is the line? Both parents and children deserve to know.

I think parents and children do know. It's cops and judges who don't seem to get it.