Anything that uses radio waves can be intercepted, recorded, analyzed, decoded and used. Just matter of time.
This is not quite correct. RPVs are mostly autonomous and human intervention is quite limited. Satellite links provide data transmission back to the ground operator. You can bet that command and control signals, as well as data are all encrypted, and if the Iranians are breaking these kinds of codes and exploiting them in real time, then some folks at NSA need to be fired. Jamming does not good because the system is designed assuming that it will be jammed, which is why flight is mostly autonomous.
They might have shot one down, or it might have gone down because of a technical mishap, but that is why you fly UAVs, so that you can risk flying them in a high threat environoment. By comparison to a manned aircraft they are cheap.