Mueller, in Senate testimony Wednesday, acknowledged for the first time that the Federal Bureau of Investigation uses "very few" drones in a limited capacity for surveillance.
"It's very seldom used and generally used in a particular incident when you need the capability," Mueller said when asked about the bureau's use of pilotless aircraft with surveillance capabilities. "It is very narrowly focused on particularized cases and particularized needs."
Mueller's remarks about the FBI's use of drones - and the regular use of the vehicles by other law enforcement agencies - come as lawmakers and civil liberties groups are raising concerns about the reach of the government in the wake of the disclosure of two highly classified National Security Agency surveillance programs.
Leaks by former intelligence contractor Edward Snowden to The Washington Post and Britain's Guardian newspaper unveiled surveillance programs that sweeps up telephone call data from millions of U.S. citizens as well as Internet traffic that the Obama administration says involves foreigners based outside the U.S. suspected of plotting terrorist attacks.
The revelations about the surveillance programs have reignited a political debate that has repeatedly flared since the Sept. 11, 2001, attacks on the U.S. about the balance between civil liberties and protection from terrorism.
Lawmakers, including Senate Judiciary Committee Chairman Patrick Leahy, D-Vt., and civil liberties groups have raised concerns about the impact on privacy of drones used by federal law enforcement agencies. The Homeland Security Department regularly deploys drones to oversee the southern border.
"This is a burgeoning concern for many of us,' Sen. Mazie Hirono, D-Hawaii, said of drone use, by the government as well as by private companies or individuals.
The Federal Aviation Administration estimates there may be about 10,000 active commercial drones in five years. Bills have been introduced in at least 18 states to limit or regulate such aircraft, according to the National Conference of State Legislatures.
Leahy said during a March hearing on drones that he was "convinced that the domestic use of drones to conduct surveillance and collect other information will have a broad and significant impact on the everyday lives of millions of Americans going forward."
Mueller said the FBI is in "the initial stages" of formulating privacy guidelines related to its drone use.
"There are a number of issues related to drones that will need to be debated in the future," Mueller said. "It's still in its nascent stages, this debate."
Homeland Security Secretary Janet Napolitano said in a June 15 Bloomberg Television interview that the operation of unmanned aircraft makes "our forces on the ground more effective" and that privacy concerns are regularly weighed and addressed by an office embedded within the department.
"We are constantly making sure that we are abiding by restrictions and doing what we need to do from a border security perspective without invading American's rights," Napolitano said in the interview for the program, "Political Capital with Al Hunt."
Annual spending on unmanned aerial vehicles worldwide will almost double to $11.4 billion in the next decade, according to an April 2012 report by Teal Group, a defense industry consultant based in suburban Fairfax, Va. Major drone makers today include Northrop Grumman, based in suburban Falls Church, Va.; General Atomics Aeronautical Systems, in Poway, Calif.; and AeroVironment, in Monrovia, Calif., according to Teal.
More Nation & World Headlines
Marines seek to close combat jobs to women Republicans jockey for conservative credibility Captive snake gives birth with no mate Obama nominates openly gay Eric Fanning as Army chief Why do the rich clean up on entitlements? Details emerge in Waco biker shootings More young adults live in parentsí basements Bill Clegg, Lauren Groff among nominees for book awards
Our new comment system is not supported in IE 7. Please upgrade your browser here.