DEW attack in Canneto di Caronia?

[ArMaP]

The problem is that signals can be made to travel through the power conduits...

It's true that in normal circumstances it is difficult to create a real Faraday cage, and if the problems affect all the electric circuits, including the power source for the appliances inside the Faraday cage, then the cage will not be effective, but that's something an oscilloscope could show.