Sometimes its the child, but sometimes its you

There is a three year old girl lying upstairs in her bed, or stomping across her floor, who has learned if she throws a fit, her mommy will make it ok. But what is OK? Is it okay for her to get into objects which will cause her harm? If she is getting in bigger trouble for her behaviors then is it okay at all?
Many times in today's world you hear about children who are doing horrible, horrible things. Shootings at school, kidnapping and killing, torture, and I sometimes think, what horrible children.
But sometimes when I am at a store, and the child throws the fit, and mommy gives in, instead of making a scene, then I wonder, who is at fault.
If the parents of some of the children, were more connected, took their doors off, took away the computer, didn't make it all ok for them, perhaps they would have learned better ways to keep themselves occupied.
In 1992, 2 10 year-old boys took a 2 year-old child, tortured and killed hhim. Where were the parents of these boys, as they spent hours torturing this boy? And becasue they are children, we make it all ok. They get new names so they don't have to face people who hate them for what they did, but if they are bad, they go back to jail. One already has.