The movie Small Soldiers is totally fiction, but the one part of that movie that made "sense" was that because the toy robots were so small, they had basically no shielding whatsoever, so the protagonist just had to haul a large wrench/ spanner up a utility pole, and connect the positive and negative terminals on the pole transformer. It blew up of course, and blew the protagonist off the pole IIRC. That also caused a small (2-3 city block diameter) EMP that shut down the malfunctioning soldier robots.

I realize this is a total fantasy/ fictional story, but it did highlight the major flaw in these drones. You can either have them small, lightweight, and inexpensive, or you can put the shielding on. In almost all cases when humans are involved, we don't spend the extra $$$ and mass to properly shield ourselves from the sun, much less other sources of radiation. This leads me to believe that we wouldn't bother shielding these low cost drones.