JAWUG

On average every square km of South African highveld and Natal receives 7 direct lightning strikes per annum.

During a storm, A high DC voltage charge develops between the bottom of the storm cloud and the ground. When the voltage gets high enough, a massive breakdown of the air dielectric occurs, resulting in a lightning strike. Benjamin Franklin and other scientists believed lightning was electricity. In 1752 he proved it with his kite experiment. His 21 year old son William was the only witness. He thought that lightning would be preventable by using an elevated rod connected to the earth to empty static from a cloud. What he invented and put to use was the lightning rod. Since then, lightning rods have been the solution to protecting life, property and avoiding a possible fire to dwellings,trees and other tall structures. There are hundreds of patents that go back as far as 150 years. If you are putting up a mast with some antennas on it you should earth it. Most hardwares stock ground spikes and a length of copper wire costs next to nothing. This will ensure that if lightning does hit the mast it has a nice low resistance path to ground. Much cheaper than if it goes to ground through your APs, switches, PC's, DSL routers, etc. Typically electronics are very allergic to high voltage even at very low amps.

How can you protect yourself even more?

While nothing can protect equipment from a direct lightning hit, surge protectors can help to minimize the damage caused by nearby lightning strikes. Surge protectors operate by connecting Transorbs or Varistors from data lines to ground. Surge protectors have no effect on normal circuit voltages, but can act quickly to divert large voltage spikes to ground and away from sensitive components. Gas Arrestors are typically used to protect wifi equipment in a similar way. Gas ionises in a chamber and the spike is shunted to ground. http://en.wikipedia.org/wiki/Lightning_arrester

What is ground really ?

http://en.wikipedia.org/wiki/Ground_%28electricity%29

And this is what an omni looks like thats been hit .. the marks are scars from the lighning .. I have tried to clean it with spirits .. but the material has been etched by the high voltage.