The CIA recruited double agents from droves of suspected terrorists held in Guantanamo Bay in a program that lasted for several years post 9/11, promising prisoners freedom, safety, and a lush payoff in exchange for helping the U.S. infiltrate al-Qaeda abroad. According to the Associated Press, the classified operation was carried out in a series of relatively swank cottages dubbed "Penny Lane" from 2003-2006:

Candidates were ushered from the confines of prison to Penny Lane's relative hominess, officials said. The cottages had private kitchens, showers and televisions. Each had a small patio. Some prisoners asked for and received pornography. One official said the biggest luxury in each cottage was the bed — not a military-issued cot but a real bed with a mattress. The cottages were designed to feel more like hotel rooms than prison cells, and some CIA officials jokingly referred to them collectively as the Marriott.

Conditions at Penny Lane must have far exceeded those at Guantanamo Bay, where detainees — many of whom were incarcerated for years without trial — were allegedly tortured. However, some of the men who went through the program, which ended in 2006, did indeed help the CIA hunt down and kill other al-Qaeda operatives. Others disappeared. According to the AP, at least 16 percent of those freed from Gitmo were identified as rejoining the fight against Washington, with another 12 percent suspected of doing so. It is unclear whether those tapped at Penny Lane were a part of either group.

The program is also an example of relaxed judicial standards in the years since 9/11 and the Patriot Act. Per the AP:

Officials knew there was a chance that some prisoners might quickly spurn their deal and kill Americans. For the CIA, that was an acceptable risk in a dangerous business. For the American public, which was never told, the program was one of the many secret trade-offs the government made on its behalf. At the same time the government used the risk of terrorism to justify imprisoning people indefinitely, it was releasing dangerous people from prison to work for the CIA.

President Obama, who promised to shutter the controversial facility during his 2008 campaign, but has since dragged his feet on the closure, reportedly requested a review of Penny Lane participants, who were providing drone strike intel. Judges began hearing testimony from suspects remaining at Guantanamo Bay in August, when the mostly secret trials began.