These groups are demanding due process and rights for those that do not deserve them, other than documenting that they are enemy combatants or terrorists. They also act as mouthpieces to pass on propaganda and false claims of torture by the US. (as opposed to isolated cases of torture)
This 'harassment' by the rights groups might actually create a situation where the US will simply prefer to neutralize terror suspects, given an option.
Since these organizations are making life difficult for the US to capture and hold terror suspects, it becomes much easier to just kill them off. For example:
A building is identified as a terrorist safe house. While it would make sense to capture those inside for questioning, despite a known danger that those inside, known to be armed will fight back, the Government might opt to instead have an air strike destroy the building. This will avoid the issue of dealing with the hassle of detaining 20-plus ‘insurgents’ for the opportunity to interrogate them. They will still leave behind a good deal of material in the rubble for intelligence to review.
Confusion lingers over Australian anti-terror laws - FT
CIA Holds Terror Suspects in Secret Prisons – Washington Post