(WASHINGTON) -- The FBI does fly spy drones over the U.S.
FBI Director Robert Mueller made that admission before the Senate Judiciary Committee on Wednesday during his testimony about the National Security Agency surveillance programs.
According to Mueller, the FBI deploys these unmanned planes in "a very minimal way and very seldom" and his bureau is working to develop guidelines for their future use so as to relieve concerns of privacy advocates and civil liberties groups.
While not disclosing what exactly the drones are being used to survey, Mueller said their deployment was "narrowly focused on particular cases and particular needs.''
As for the NSA programs revealed by contractor-turned-leaker Edward Snowden, Mueller maintained they were necessary tools to uncover terrorist plots.
He rejected calls to scale them back, telling lawmakers, "Communications are the soft underbelly of terrorist [operations]. If that goes dark on us, we will be sitting waiting for the next attack.''
As for attempts to prosecute Snowden for revealing classified information, Mueller remained mum on the subject.
The outgoing FBI chief also addressed the Internal Revenue Service targeting Tea Party and other conservative groups, saying dozens of special agents had been dispatched to conduct a criminal investigation and promising to "pull no punches" if wrongdoing is uncovered.
Mueller also rejected some lawmakers' assertions that the probe into the IRS was "languishing."
Copyright 2013 ABC News Radio