Today, an FBI and the Department of Homeland Security joint bulletin to law enforcement obtained by CBS warned of possible retaliation from the killing of Osama bin Laden.
The bulletin notes that federal law enforcement officials are more concerned about possible retribution from "homegrown violent extremists" than organized plots from al-Qaeda. They say they expect to see an increase in "violent extremist rhetoric calling for retaliation".
Law enforcement notes that there are "no indicators of advanced al-Qaida plotting in the United State," but they caution, "the remaining members of al-Qaida core could accelerate any ongoing plotting..."
The bulletin indicates law enforcement believes the two most active al-Qaeda affiliates capable of planning an attack are al-Qaeda in the Arabian Peninsula (AQAP) and an "ally" of Al Qaeda Tehrik-e Taliban Pakistan (TTP) which they note is responsible for the May 1, 2010 attempted car bombing in Times Square.
The bulletin notes a TTP spokesperson has already indicated they would "avenge" Osama bin Laden's death.
The military is also beefing up security at bases around the country and indicating visitors should anticipate delays at base entrances.