A federal audit has revealed the FBI has been operating drones inside the United States since 2006 at a cost of more than $3 million. In total, the Justice Department has spent nearly $5 million on drones, according to the report, which was issued by the agency’s inspector general. That includes funds to several local police departments, which auditors said the department has failed to track. The report urged officials to develop new guidelines to protect privacy, saying drones raise “unique concerns about privacy.” Drones currently operate under the same rules as manned surveillance planes.