It doesn't work:
The application of techniques such as waterboarding -- a form of simulated drowning that U.S. officials had previously deemed a crime -- prompted a sudden torrent of names and facts. Abu Zubaida began unspooling the details of various al-Qaeda plots, including plans to unleash weapons of mass destruction.
Abu Zubaida's revelations triggered a series of alerts and sent hundreds of CIA and FBI investigators scurrying in pursuit of phantoms. The interrogations led directly to the arrest of Jose Padilla, the man Abu Zubaida identified as heading an effort to explode a radiological "dirty bomb" in an American city. Padilla was held in a naval brig for 3 1/2 years on the allegation but was never charged in any such plot. Every other lead ultimately dissolved into smoke and shadow, according to high-ranking former U.S. officials with access to classified reports.
"We spent millions of dollars chasing false alarms," one former intelligence official said.
Despite the poor results, Bush White House officials and CIA leaders continued to insist that the harsh measures applied against Abu Zubaida and others produced useful intelligence that disrupted terrorist plots and saved American lives.