According to a press release by Congressman Adam Schiff:
During a hearing before the House Judiciary Committee today, Rep. Adam B. Schiff (D-CA) questioned Attorney General Alberto Gonzales about the NSA's secret domestic wiretapping program. The Administration has cited the Authorization to Use Military Force and the commander in chief powers as authorizing the NSA to intercept international communications into and out of the U.S. of persons linked to al Qaeda or related terrorist organizations.
After citing his concerns that there was no limiting principle to the Administration's claim of authority in the War on Terror, Rep. Schiff asked the Attorney General whether the Administration believes it has the authority to wiretap purely domestic calls between two Americans without seeking a warrant.
"I cannot rule that out," responded the Attorney General.