"The most dangerous people on Earth" is how Condi Rice refers to our prisoners at Guantanamo Bay. Let's apply some logical deduction to that statement, shall we?
To be one of the most dangerous people on Earth, you need an education. Pure evil alone is not enough. Did we consider Jeffrey Dahmer one of the most dangerous people on Earth? No. He certainly was a dangerous person. One who caused a lot of damage. But he does not make the list of the most dangerous people on Earth.
Because he did not endanger a way of life, he did not impact thousands and thousands of people's lives, he did not motivate others to follow his path, he lacked the knowledge and skill to disrupt any nation's infrastructure.
All those skills require a mechanical engineer, a doctor, a chemical engineer, etc. People like that will know how to hit a system in its weakest points. They will have the intellectual and organizational skills to plan, organize, recruit and execute a complex operation. They will be able to pick and plan based on maximum damage. They will be able to blend into a population.
Jeffrey Dahmer could not do any of these things.
Now let's look at the idea of teenagers as some of the most dangerous people on Earth. No teen will have the education and the experience to be able to pull off a major terrorist attack. How then could they be among the most dangerous people on Earth? They can't.
Even if, supposing for a moment, the teens held in detention at Guantanamo Bay were evil and depraved, the extent of damage they could do alone is limited to individual actions, or little more than that. No teenager is motivating hundreds of people to strap bombs on their backs and blow themselves up.
Studies have shown that humans don't reach moral maturity until the late twenties. So it is easier to pull teenagers into violent activities than it is adults.
Conclusion: There is no reason on Earth for any teenager to be held as a terrorist at Guantanamo Bay. Oh, and for all of you jerks who say "if you knew what I knew, you would think differently" Econo-Girl can only say this: I know everything you know, and you're still fucking wrong.