You can get RF protected wallets to protect your credit card from someone reading it.. You can also get RF credit card selves to protect your card. You can use metal screen to protect things if the holes in the screen are smaller than the wavelength of what ever the problem is. I don't know about EMP though.
The rotation of the earth generates power in the north-south power lines. An emp would generate high voltage in these lines.
20 posted on 04/27/2022 9:00:47 AM PDT by mountainlion
(Live well for those that did not make it back.)