As of Sept. 6,  the U.S. had transferred or released about 435 prisoners from Guantanamo to more than two dozen nations since the detention center opened in January 2002. Most were subsequently released by their home countries.
About 340 detainees remain 340 there today. In response to a Freedom of Information Act request, the Pentagon "handed over transcripts of 64 [ARB] hearings" conducted in 2006. These were the second round of hearings. Some transcripts were withheld.
It's true that some were militants who openly oppose US foreign policy. Others had military training in Afghanistan... to fight the Northern Alliance war lords. Maybe some were desperate and saw military service as a way out of a life going nowhere.... Naw, that never happens.
For what appears to be the majority, there's no evidence.
... in case after case, the source of often very serious accusations against the men is unclear, hamstringing detainees' efforts to contest the allegations.
Read: Hamstringing the "presumed guilty" from proving their innocence.
Or, perhaps they are simply guilty by association. The AP article provides an example of the US applying the principle "guilt by association" and holding a person, without charge, without counsel, for five years:
Ayman Saeed Abdullah Batarfi, a doctor from Yemen, acknowledged treating wounded al-Qaida fighters at Tora Bora in Afghanistan, but said he was forced to do so.
"I deny these allegations against me," Batarfi said. "It is the same information used against me last year. ... I don't want to be back to the same point again next year."
Aside from the fact that these are mostly powerless dark-skinned people, there is an explanation. Most of them were set up. Most of them are in US hands because the US had a bounty for "terrorists" and people collected on the bounty by turning over... anyone.
"You did not catch us in Pakistan — we were sold in Pakistan," said Abdennour Sameur, an Algerian. "The Pakistani army was very poor, that's why they were selling us to you."
What the AP didn't report:
Professor Mark Denbeaux at Seton Hall Law School has conducted a profile of 517 Guantanamo detainees using data from the US Department of Defense. Among other things, he found that only 5% were captured by the US.
Denbeaux found that
as many as 86 percent were handed to US for bounties.
A large proportion of the Guantanamo cases are thinner than "guilt by association." Many are simply "guilty by bad luck" of being fingered for a bounty. They aren't terrorists. They're innocent.