That's probably one of the dumbest things I've seen done with an RC airplane. Fly an incredibly small target that you very likely couldn't see anyway in clouds in the way of airplanes with people on board.
Bad damn idea.
As you can see, there is a TV camera on board. Most likely, they are flying using the monitor as vid source and not the naked eye.
Hams do this quite a bit with ATV on 432 mHz as the video source, but do not fly near airports or much above 2,000'.
At 6,000' anywhere near where light aircraft are is not a good idea....just for safety's sake.
ROX