Also using Stingrays to track/intercept mobile phones.
"Each weekday, dozens of U.S. government aircraft take to the skies and slowly circle over American cities. Piloted by agents of the FBI and the Department of Homeland Security (DHS), the planes are fitted with high-resolution video cameras, often working with “augmented reality” software that can superimpose onto the video images everything from street and business names to the owners of individual homes. At least a few planes have carried devices that can track the cell phones of people below. Most of the aircraft are small, flying a mile or so above ground, and many use exhaust mufflers to mute their engines — making them hard to detect by the people they’re spying on.
The government’s airborne surveillance has received little public scrutiny — until now. BuzzFeed News has assembled an unprecedented picture of the operation’s scale and sweep by analyzing aircraft location data collected by the flight-tracking website Flightradar24 from mid-August to the end of December last year, identifying about 200 federal aircraft. Day after day, dozens of these planes circled above cities across the nation.
The FBI and the DHS would not discuss the reasons for individual flights but told BuzzFeed News that their planes are not conducting mass surveillance."