Lightning causes havoc on electronics. Every year it causes more damage than hurricanes, tornadoes and floods combined, and it's extremely unpredictable. It starts by sending out thousands of leaders in every direction, even up into the sky. Each leader splits off again and again in search of ground or something it can discharge into. Lightning rods are just a hope and a prayer that a leader will find the rod first. Some instances have even been recorded of lightning striking from the other side of a mountain over 5 miles away. There is no way to stop it and, if you don't protect your equipment, one day lightning may very well take it out.

In fact, there have been cases where a lightning strike caused a big enough surge to kill equipment miles away through the power lines. Lightning isn't the only way that electricity can render your rig useless, however. Unstable power might take longer to cause a shut down, but the end result is the same: replacing equipment. Unstable power can be the result of bad power lines, an overloaded substation or even just a low quality power converter in your equipment. So it's vitally important to be sure that at least your own hardware isn't going to kill itself. In the PC market, that means you don't skimp on a power supply.