[Daniel.]

Dude its so you cant walk past an "unsecured" wireless network and suddenly your computer ends up dead the next time you turn it on.

Wireless networks or wireless anything are the most unsecured devices in the world.
Even with SSLID's as well as multiple encryption algorithms, wireless networks can be hacked in minutes or even seconds. Leaving computers on the network completely vulnerable.

Just because your don't share a folder on your computer doesn't mean that someone else cannot leech the contents from you, or delete it right infront of your eyes.

Computers are some of the most unreliable and unsecured devices on the planet. If not the most. As for wireless, stay away from it and always turn your laptops wireless off when your around town or an internet cafe or anywhere that an unsecured network could be..

Typical story. My school (my old school I don't go to school anymore) upgraded to wireless and the day after they did they got hacked and some complete random with a laptop crushed our whole network and workgroup from a few miles away..
We didn't have computers up for even the internet for the last term... which means it was impossible to study at school for my School Certificate..

THATS why computers have that switch. As for that keep it off your tummy it'll burn you when it gets to hot and your body heat isn't good for it.

P.S You can NEVER disable wireless. You have to take your wireless card out from your computer to disable it. Or you have to use that switch. If you turn it off in the options your computer can still be hacked/pinged/discovered on a network/leeched from or whatever else. Hence the switch.