As to the details:

The two-page e-mail that references an Executive Order states that the President directly authorized interrogation techniques including sleep deprivation, stress positions, the use of military dogs, and “sensory deprivation through the use of hoods, etc.” The ACLU is urging the White House to confirm or deny the existence of such an order and immediately to release the order if it exists. The FBI e-mail, which was sent in May 2004 from “On Scene Commander--Baghdad” to a handful of senior FBI officials, notes that the FBI has prohibited its agents from employing the techniques that the President is said to have authorized.

Another e-mail, dated December 2003, describes an incident in which Defense Department interrogators at Guantánamo Bay impersonated FBI agents while using “torture techniques” against a detainee. The e-mail concludes “If this detainee is ever released or his story made public in any way, DOD interrogators will not be held accountable because these torture techniques were done [sic] the ‘FBI’ interrogators. The FBI will [sic] left holding the bag before the public.”

The document also says that no “intelligence of a threat neutralization nature” was garnered by the “FBI” interrogation, and that the FBI’s Criminal Investigation Task Force (CITF) believes that the Defense Department’s actions have destroyed any chance of prosecuting the detainee. The e-mail’s author writes that he or she is documenting the incident “in order to protect the FBI.”

Reuters has more.