Protected items inside the cage should be suspended from contact with the cage itself according to articles I have read on the topic. FWIW.
Interesting read is Ted Koppel's book "Lights Out". One particular item in the book is the attack on a major substation in Kali. Our infrastructure is vulnerable and has been a topic of national concern. From what I can gather, not much has been done to protect our system. Maybe the military has done something but it is not public info if they have.
An EMP attack is a real possibility and not pure bunk.
