Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, and Army Gen. David H. Petraeus, commander of U.S. Central Command, sign autographs for the grandchildren of Army Gen. Keith Alexander during the activation ceremony of U.S. Cyber Command on Fort Meade, Md., May 21, 2010. Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, and Army Gen. David H. Petraeus, commander of U.S. Central Command, sign autographs for the grandchildren of Army Gen. Keith Alexander during the activation ceremony of U.S. Cyber Command on Fort Meade, Md., May 21, 2010. SHARE: Download: Full Size (3.84 MB) Tags: Photo Essays Credit: VIRIN: 502454-Q-MBD56-351.jpg Photo Gallery