Here is a CNN report on it http://money.cnn.com/2016/12/02/technology/kremlin-gps-signa...

They spoof no-fly zones to trick the drones that abide by them. It's hard to image building or retrofitting a surveillance or weapon drone and leaving limiters in place.

I first heard about it on a running forum but I cannot find the link. Apparently, joggers were getting an extra 20 km on their runs because of the spoofing.