just after noon On a Saturday last month, a Skydio X10 quadcopter hovered about 200 feet above a San Francisco apartment complex, watching police pursue a man hiding behind a parked car. The target of this chase lay flat on the pavement, apparently unaware that he was still in sight of the flying eye above his head. In fact, the 5-pound drone had already followed him throughout the city, zooming in on the license plate of his black SUV and keeping the vehicle locked in the center of the video frame until it stopped. Now he watched the police as they approached and surrounded him.

As officers approached, the man adjusted his hiding spot and moved to the other side of the parked car. At that moment, however, another Skydio drone approached his location, one of four Skydio quadcopters that had followed the man just the previous hour. He had been called from a nearby McDonald’s, where he had been observing two people who had gotten out of the suspect’s car a few minutes earlier, and now began to observe him from a second angle.

Within seconds, three officers approached the man, two of them pointed guns at him and then tackled him to the ground as a half-dozen more police arrived on the scene. Police records provided to WIRED by the San Francisco Police Department show the entire street response that followed what the SFPD described as an alleged “auto drive/dismantle” incident — the alleged theft of auto parts or another object from a vehicle.

Drone footage posted on a public web address shows how a quadcopter approached the license plate of an SUV, followed it through traffic, and then followed the driver as he got out of the car and ran toward an apartment complex. The suspect hid behind a vehicle, then adjusted his hiding place, but was still visible to a second drone that arrived on the scene, one of four that tracked his location in a single hour and then captured police tackling him, all in response to what SFPD describes as an alleged “auto boost/dismount” incident, the theft of auto parts or another object from a vehicle.

Materials reviewed by WIRED

This glimpse of modern drone-enabled policing, including the highly sensitive video of the man’s physical takedown, was not voluntarily released by the SFPD, which, like most U.S. police departments, rarely releases drone video, even in response to public records requests. Instead, it was accidentally broadcast live to the Internet via Skydio’s website. That’s where two security researchers, Sam Curry and Maik Robert, discovered that the SFPD was leaking all real-time footage from five of its surveillance drones, including color and thermal images, the accompanying location metadata, and the names and email addresses of the drone pilots, to anyone who simply found the public web address where the videos were hosted.

Curry and Robert say they reported their discovery to Skydio about two days after discovering it, and they quickly took it offline. By then, however, investigators had watched police carry out what appeared to be multiple arrests and searches, as well as track cars and individuals from the sky, all visible on a completely public web address.

“It gives police some confidence to use these things correctly,” Curry says. “When you’re watching a live stream with a drone, you can see dozens of different apartments, you can see police approaching people, you can see arrests. The fact that all of this has been exposed seems like a really big problem from a privacy perspective.”

The leaked video captures two forced arrests (it’s unclear from the footage whether actual arrests were made), a police visit to an apartment in a high-rise apartment building, and an apparent search of an alley populated with homeless people, as well as many other more ambiguous cases in which police used drones to surveil people, vehicles, or buildings. While the stream remained active, Curry and Robert began archiving the public stream of data and video and then shared the results with WIRED.

The file Curry and Robert captured provides a detailed record of SFPD drone operations for approximately 48 hours in mid-June. It includes 60 videos from 20 separate flights, with each mission recorded from three feeds: a color camera, a thermal camera depicting people as heat signatures, and a third view from the drone’s rooftop dock. WIRED analyzed the 20 color videos with software that detects people, vehicles and other objects in the images. The review found that cameras had filmed hundreds of people and vehicles on the 20 flights. In a single frame, as a drone flew over a downtown intersection, the software counted 34 people crossing the street or standing on sidewalks. In all the videos, the images showed clear faces of dozens of people.

Together, the videos total more than three hours of color aerial footage and approximately the same amount of thermal footage. The file also includes second-by-second telemetry logs for each flight (more than 5,000 total GPS points tracked over about 44 miles) that record the latitude and longitude, altitude, speed, heading and battery level of each drone from takeoff to landing. The names and email addresses of six SFPD pilots also appear in the records.