CPS Going Nuts?

I have a real problem with Child Protective Services taking custody of a child away from her parents just because they haven't yet gone along with the prescribed treatment from a doctor. From what I've read and seen on the news, the parents wanted a second or third opinion before subjecting their daughter--who has already been through chemotherapy--to radiation. So, the state steps in and takes not just their daughter, but all four of their children. (I believe a judge has already ordered that their three other children be returned to them.) Who the hell do they think they are? When they couldn't find the mom and the girl, they went so far as to issue an Amber Alert for her. I'm sure all the parents of kidnapped children appreciated that important use of the system. I don't believe that parents should be able to deny their children necessary medical care. But, it seems that the state should perhaps seek to resolve whether this is incontrovertibly medically necessary treatment, as opposed to one or two doctors' opinions, before they go around issuing Amber Alerts and seizing custody of children from their parents.