An OLC memo advising “that caution should be exercised before relying in any respect” on John C. Yoo’s October 23, 2001 memo, Authority for Use of Military Force to Combat Terrorist Activities Within the United States.  The memo notes specific conclusions of the Yoo memo that are incorrect or highly questionable, including the Yoo memo's conclusion that the Fourth Amendment does not apply to domestic military operations designed to deter and prevent future terrorist attacks.