When I first heard about it several years ago (that last time a journalist was allowed in), I was indeed enraged. Then again, I was a minor at the time, and like any teenager aware of the law, resented the fact that I really didnt have many rights.
However, having matured somewhat, I can see that this world is indeed full of near-impossible youngsters. It disturbs me that some of these centers may not have proper safeguards to ensure that they really are a last resort, but on the other hand, I could certainly see how a parent would be in such a situation that such drastic measures would be required if they wanted their child to ever become a functioning member of society.
Regarding law and ways to deal with it, it is likely that the camp is subject only to Jamaican law, and that such organizations can deal with that sort of thing anyway. Besides, there have been lawsuits in the United States against such camps (ones in US jurisdiction) -- and none have been sucessful.
The idea that the UN or anyone else would take action against this on the grounds of fundamental human rights is about as realistic as a CoC game based in one of these places. Look back through the history of UN action, and you will see that it is utterly unable to act outside of the dictates of power politics. It either aids in what would have happened anyway (i.e. peacekeepers after agreements), does things that no country actually wants to do but looks good for political leaders (humanitarian peacekeeping such as Somalia), or gets completely ignored when it doesnt comply (Kosavo, Iraq). Similarly, never has a country taken an action against another to safeguard "fundamental human rights." There exist absolutely no enforcement mechanisms for such things. Probably, there never will.
Besides, "Depravation of Liberty" is a madady sufferd by most people in this world, not just boot camps for recalcitrant youth.
The World Court prosecutes defeated dictators and their lackies, usually at the discretion of the conquerers. The International Criminal Court is highly subject to political manipulation (there are absolutely no safeguards against the court being used as a weapon against a country that the judges at the time do not like), and the United States has said that the ICC can go to h*ll. Belgium has a law asserting that they can prosecute human rights crimes anywhere in the world, and are in the process of using it against the US and Israel for various wars (see comment RE: politicization of human rights issues), but Belguim cant actualy back up its claims to being the worldwide defender of human rights with the sort of power necessary to do so.
[Politicalish statement intentially avoid of normative judgements]