The people held in Guantanamo Bay are not POW's.
If they were, they would be entitled to more rights than they have - like for example a trial or military tribunal? And the US is not, under the Geneva convention, at war.
Strictly speaking, the Geneva convention does not apply.
In US terms they are 'unlawful combatants', which is why they are also being held in a location that does not fall under normal US law.

This is exactly the same thing that the UK government did in Northern Ireland, when it used special powers i.e. prison without trial for those they suspected as being terrorists - didn't see many people in the US supporting that!
As far as I know the majority of Americans supported the IRA terrorist campaign.

To some extent you can see the point of this, but if you really believe they are guilty, then why not put them on trial?? This is a classic case of guilty until proven innocent.

Of course I don't support terrorists, but what the US is trying to say is that after interrogating someone for two years, they still don't have any evidence ????