There are 2 main reasons -when it is overcharging in the power supply-:
The too high voltage is because of the lightning and the electronically network's fault is the much higher voltage level. The lightning caused overcharge is able to go not just to the tramway and telephone systems but to informatics and telecommunication systems, too.
Lightning causes damage not just in that exact place to where it strikes but the magnetic field with the induction also occasions damage in 1 km area.

When we want to defend against the strike of lightning we have to know that the lightning-conductor is protects us from the direct destroying effect of the high current.

One of the bad effects of stroke of lightning is the blackout and the data losing because of the blackout. The security awareness of our information is not concern only hackers and viruses but the natural disaster, too.

One way of the protection is if we buy an uninterruptible power supply, which can protect our data if there is blackout. It consists an accumulator which can register if the voltage level is changing and it turns on the accumulator by the time is necessary. There is another type of this equipment when it uses the accumulator all the time and supposing blackout the conversion is not causing problem.

You can read more: www.infosecuritylab.com