Yes, governmental agencies mask the abuse of children and operate in violation of children's rights, because they do not really care about the children. The governmental agencies that are supposed to protect children will protect politically connected families, and they will look the other way, rather than look bad in the media.
I'd like to think that abuse and rights violations of children by government agency's are individual rather than systemic, but why pretend? They're happy enough to violate and abuse adults. I'm sure there are individuals with the best intentions smothered by bureaucracy and red tape, but for the most part, the best one can hope for from the government is incompetence without the extra slice of malice that is so often present.
The latest example of child abuse on a massive scale, the Catholic church's cover up of systemic abuse of children among their clergy over decades, is only the latest example of leaders in power turning a blind eye when there are children in need. Child trafficking is now rampant, and we need to do something about it.
I am not aware of an ongoing problem where governmental agencies mask the abuse of children and operate in violation of children's rights. My family has been investigated by CPS under false claims to their anonymous help line and they were very through when they visited my residence. Of course there was nothing for them to find, but it would seem that they did their job, although it was very invasive, in my opinion.