August 7 marked the anniversary of the bombings of the U.S. Embassies in Nairobi and Dar es Salaam. Because anniversaries of such incidents are sometimes marked by similar violence, the Justice Department has put all of its employees on alert and tightened security at all of its buildings. In addition, the FBI has shut down indefinitely public tours of its headquarters because of “unconfirmed threats” to the building linked to Osama bin Laden.