FBI director Robert Mueller said Wednesday that the nation's top law enforcement bureau uses drones to conduct surveillance on U.S. soil, though only on a "very, very minimal basis."

Mueller, the FBI director since 2001 who is set to retire this year, acknowledged that his agency uses drones in its investigative and law enforcement practices, and is further working to establish better guidelines for the use of drones.

"We are in the early stages of doing that, and I will tell you that our footprint is very small, we have very few, and have limited use.

Nine 7-Eleven store owners and managers who authorities say ran a “modern-day plantation system,” employing dozens of immigrant workers at New York and Virginia convenience stores, were just one thread in a vast human trafficking and forced labor web that stretches around the world and into American homes.