Specter: Pentagon may be obstructing committee Officials ordered witnesses not to testify about secret program. WASHINGTON (CNN) -- The Department of Defense "ordered five key witnesses not to testify" about a secret Pentagon unit that some claim identified several of the 9/11 hijackers more than a year before the attacks, Sentate Judiciary Committee Chairman Arlen Specter said Wednesday. "That looks to me as it may be obstruction of the committee's activities," Specter, R-Pennsylvania, said at the start of his committee's hearing into the unit code-named Able Danger. Before Wednesday's hearing, Pentagon spokesman Bryan Whitman said the Pentagon was concerned about...