The Guardian Threat Tracking System is a reporting system used by the United States Federal Bureau of Investigation to track threats and other intelligence information. It was established to collect data on terrorist threats and suspicious incidents, at seaports and other locations, and to manage action on various threats and incidents.  Although Guardian was first used the latest of 2005, on August 21, 2007, the US Department of Defense announced that Guardian would take over data collection and reporting which had been handled by the TALON database system. 
- The Federal Bureau of Investigation's Efforts to Protect the Nation's Seaports, Office of the Inspector General, US Department of Justice, March 2006, accessed 8/21/07.
- Defense Department to Close TALON System Archived 2007-09-27 at the Wayback Machine Sgt. Sara Wood, USA, American Forces Press Service, 8/21/07.