You would think that with the way they work, Microwave would hava a sort of ESG effect - the microwaves would induce an electric current in the metal, frying the electrical systems inside (same reason why you don't put metal in a microwave, or if you do, you see it arcing)
Anyone see the movie "The Core", and how the sun's microwaves melt the Golden Gate Bridge.... pretty cool, don't know if that would really happen....