They have infected the control computers, and the keylogger (and mouselogger?) is logging all the commands being given. If they can come this far, how difficult is it to, say, insert spurious "fire" commands? Or redirect the drone to some other place?
My point was that there isn't any indication from this report that the drones were purposefully infected. Random infections are probably inevitable due to probabilities, but deliberate ones seem quite a bit harder.
Indeed, the barrier to entry has been lowered by a staggering amount. Previously, terrorists had to pay many millions of dollars to General Atomics to rain down death from above.
