In 1859, a huge solar storm called the Carrington Event damaged what little electrical infrastructure existed in the world at the time. If a similar storm happened now, the damage to our electricity-dependent modern world be severe.
Nuclear weapons detonated high in the atmosphere could have the same effect. This type of attack is called an electromagnetic pulse (EMP) attack and national security agencies have considered how to prepare for and mitigate against such destruction.
What would you, as an individual, do in order to prepare for life after an EMP attack? Some preppers and the companies that sell products to them consider options. MOS Equipment is a firm that specializes in protective gear, including a tent that can shield a car's sensitive electronics from an EMP. It's basically a huge Faraday cage.
-via David Thompson