“Spoofing a GPS receiver on a UAV is just another way of hijacking a plane,” Humphreys told Fox News.

In other words, with the right equipment, anyone can take control of a GPS-guided drone and make it do anything they want it to.

“Spoofing” is a relatively new concern in the world of GPS navigation. Until now, the main problem has been GPS jammers, readily available over the Internet, which people use to, for example, hide illicit use of a GPS-tracked company van. It’s also believed Iran brought down that U.S. spy drone last December by jamming its GPS, forcing it into an automatic landing mode after it lost its bearings.

It looks like we have something more than radio jamming to worry about. Although the military drones use encrypted signals, I believe that it can be cracked just like any other encryption.