American authorities appear to have raised their threat level as a wartime precaution, rather than in response to a specific threat, though the Federal Bureau of Investigation gave warning last week that a particularly dangerous al-Qaeda suspect is on the loose and may try to slip into the country.

ECONOMIST: Tense times at home

The Intelligence Oversight Board (IOB) was created in 1976 by President Ford in response to recommendations made by the Rockefeller Commission calling for a Presidential-level body with specific oversight responsibilities for the legality and propriety of US intelligence activities.

WHITEHOUSE: History