Children have no right to privacy? I suppose they are always conspiring to do wrong. Every recording is that "bad" song they are not supposed to be listening to. Every page they wish to visit on their computer is porn. Every phone call is a "date" and will lead to fornication. Everything they do at school has to do with the flag salute, fornication, and/or a holiday celebration or they are going to start using drugs. Even within their own room, they are always masturbating or planning on doing fornication or other forbidden activity.
Which is not right. I wonder what would happen if you give a 13-year old a computer, that sits in their own room. Most of the visited web pages will be clean--if you don't keep pushing the issue, they are not very likely to be watching porn at that age (just put a filter in the computer that makes it difficult to access adult content). And, if there weren't so damn many stupid rules, there would be much less need to closely supervise children. Even the drugs--if children are kept busy learning things (and the education indoctrination you get in school is not the right way), they are not going to want to take drugs. Really, the only rules you need are against first-strike offensive acts against others or their property--and you are going to pretty quickly find out if that is going on without major invasions of their privacy.
Now, if the children deserve their privacy, the government doesn't. Those making the rules do not have any right to privacy in doing so, because people are going to be affected. Are they claiming to abide by the Bible? They need to make the rules in the open, right in front of people that will scrutininze those rules with that same Bible. The same with the government and the Constitution. Individuals need privacy--ruling bodies do not.