Is electromagnetic protection useful?

Absolutely. The biggest risk to your digital/magnetic information carriers, is electromagnetic radiation.
It can be reprocessed by natural phenomena such as lightning and solar storms that can cause severe damage to electonics.
Yet we go one step further by immediately also protecting them from artificially generated dangers such as, for example, an e-bomb.
This is an explosive that generates a strong electromagnetic pulse that destroys any electromagnetic carrier. The bomb can be manufactured by simple means and quite cheaply, e.g. by terrorists who want to disrupt the economy.
Your magnetic carriers stored at Merak are shielded from this because our e-bunker is built around a Faraday cage.

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