Robert Mueller: FBI uses drone surveillance in U.S.

At a congressional oversight hearing Wednesday, Iowa Sen. Chuck Grassley asked Federal Bureau of Investigation Director Robert Mueller, "Does the FBI use drones for surveillance on U.S. soil?"

"Yes," Mueller responded, though he quickly added that FBI drones are "very seldom used and generally used in a particular incident where you need the capability."

Mueller confirmed to lawmakers that the FBI owns several unmanned aerial vehicles (UAVs), but has not yet adopted any policies or guidelines to govern their use. He said the FBI has only just begun to establish rules for the drone program.

Mueller briefly addressed the controversial National Security Agency surveillance program recently exposed by Edward Snowden. Mueller confirmed that 22 agents have access to a vast surveillance database, including 20 analysts and two overseers.

California Sen. Dianne Feinstein, who supports the NSA's data collection program, nonetheless told Mueller that drones represent a significant threat to Americans' privacy.

"I think the greatest threat to the privacy of Americans is the drone, and the use of the drone and the very few regulations that are on it today, and the booming industry of commercial drones," Feinstein said.

When asked what, if any, privacy protections are in place, Mueller replied that drone deployment "is very narrowly focused on particularized needs in particularized cases, and that is the principle of privacy limitations we have."

When Sen. Al Franken, D-Minn. asked Mueller if the FBI would consider being more open about surveillance methods, Mueller warned it could risk national security.

"There is a price to be paid for that transparency," Mueller said. "I certainly think it would be educating our adversaries as to what our capabilities are."