American researchers took control of a flying drone by hacking into its GPS system – acting on a $1,000 (Â £640) dare from the US Department of Homeland Security (DHS).
A University of Texas at Austin team used “spoofing” – a technique where the drone mistakes the signal from hackers for the one sent from GPS satellites.
The same method may have been used to bring down a US drone in Iran in 2011.
Analysts say that the demo shows the potential danger of using drones.
Drones are unmanned aircraft, often controlled from a hub located thousands of kilometres away.
They are mostly used by the military in conflict zones such as Afghanistan.
Todd Humphreys and his colleagues from the Radionavigation Lab at the University of Texas at Austin hacked the GPS system of a drone belonging to the university.
They demonstrated the technique to DHS officials, using a mini helicopter drone, flown over a stadium in Austin, said Fox News, who broke the story.