Right, a faraday screen only works if it has somewhere to drain the energy off to, specifically a ground. If there isn't a huge welding wire connected to your altoids tin on one end and a copper rod driven deep into the ground on the other end, sorry, no protection. Same goes for cars, portable radios, flashlights, bicycles, cordless phones, cordless power equipment.... you get the idea.

While an EMP has a localized destructive effect on solid state circuits, it has a much broader temporary interference effect on same. You may be 50 miles or more from a major EMP event, and suddenly your flash mem stick is wiped clean, or your computers bios is gone, or your ipod has lost all your favorite songs.

Lightning is also an EMP, just not as strong as a thermonuclear detonation. Large meteors coming down through the atmosphere can also cause an EMP, though like the thermonuclear device ones big enough to blow circuits generally have much worse direct effects.

A really big problem we had with electronics aboard ship and up on hilltops was static precipitation. It is a localized type of EMP caused by the movement of dry air across the surface of the antenna. One way to isolate your antenna system without using those big honking diodes is to install a ferrite bead at the coax connection to the radio, or even inside the radio in some models. Isolators also work pretty good, though they can be defeated by static discharge.

Gosh, there are so many things that can be done. I guess them old tube jobs do still have some purpose. <img src="/images/graemlins/laugh.gif" alt="" />