The use aerial drones within the United States could pose a terrorist threat, according to Rep. Michael McCaul (R-TX), chairman of the House Subcommittee on Oversight, Investigations, and Management.

"The Department of Homeland Security's mission is to protect the homeland," he said at a hearing on Thursday. "Unfortunately, DHS seems either disinterested or unprepared to step up to the plate to address the proliferation of Unmanned Aerial Systems in U.S. air space, the potential threats they pose to our national security, and the concerns of our citizens of how drones flying over our cities will be used including protecting civil liberties of individuals under the Constitution.

"For example, in discussions with my Subcommittee staff prior to this hearing, Department officials repeatedly stated the Department does not see this function -- the domestic use of drones -- as part of their mission and has no role in domestic unmanned aerial systems. I strongly disagree."

The Federal Aviation Administration has currently authorized about 100 different entities to fly drones domestically. The number of law enforcement agencies and other entities authorized to use drones is expected to rapidly increase thanks to a FAA funding bill passed this year. The FAA plans to allow for the deployment of privately-operated drones within the United States by 2015.

"DHS’s lack of attention about this issue is truly incomprehensible," McCaul said. "It should not take a 9/11 style attack by a terrorist organization such as Hezbollah or a lone wolf inspired event to cause DHS to develop guidance addressing the security implications of domestic drones."

He noted that researchers at the University of Texas were able to hack into a drone while it was in mid-flight, taking control of the aircraft while simultaneously tricking it into thinking it hasn’t strayed off course.

"These findings are alarming and have revealed a gaping hole in the security of using unmanned aerial systems domestically," McCaul said. "Now is the time to ensure these vulnerabilities are mitigated to protect our aviation system as the use of unmanned aerial systems continues to grow."

Watch video, courtesy of the Associated Press, below: