DOJ’s IG on Cheney’s warrantless wiretap program:
DOJ OIG found it difficult to assess or quantify the overall effectiveness of the PSP program as it relates to the FBI’s counterterrorism activities. However, based on the interviews conducted and documents reviewed, the DOJ OIG concluded that although PSP-derived information had value in some counterterrorism investigations, it generally played a limited role in the FBI’s overall counterterrorism efforts.
CIA IG on Cheney’s warrantless wiretap program:
CIA OIG determined that the CIA did not implement procedures to assess the usefulness of the product of the PSP and did not routinely document whether particular PSP reporting had contributed to successful counterterrorism operations. … consequently, it is difficult to attribute the success of particular counterterrorism case exclusively to the PSP.
[snip]
Officials also told the CIA OIG that working-level CIA analysts and targeting officers who were read into the PSP had too many competing priorities, and too many other information sources and analytic tools available to them, to fully utilize PSP reporting.
CIA’s IG on Cheney’s torture program:
As the IG Report notes, it is difficult to determine conclusively whether interrogations have provided information critical to interdicting specific imminent attacks.