So should you be hiding your wireless network? Should you be closing your Airport network? Should you be not broadcasting your SSID (service set identifier)?
Some people do this to make their network invisible.
Most people are not aware that hiding your SSID or “closing” your network, does not in fact make your network invisible.
All it does is stop broadcasting your SSID (network name).
Your network is still broadcasting and therefore detectable.
I have a (modern) Sony VAIO which can pick up closed networks without any extra software – the ability is built into the latest intel chipsets.
As well as your network still broadcasting your network will also “broadcast” your SSID everytime a client joins your network.
Why?
Well you want to join the network, so you tell the router that you want to join.
You tell it the SSID, it says okay and lets you join.
When you told it the SSID, this was broadcast in the clear and can be easily picked out by “sniffer” programmes.
Exactly the same process can be used to sniff out the the authorised MAC address if you use MAC address access control.
Unfortunately “Closed” networks, MAC access control lists, and reduction in transmission power are all more “feel good” security rather than real security. All these various approaches are dated and mistakenly lead to overconfidence.
They’re like putting a brown paper bag over your wireless router to “secure it”, it may make you feel better, but adds no security whatsoever.
WPA is your friend if you value wireless security.
Photo source.
, I was quite impressed that the price for the film was only £6.99 – and that seemed to explain why it was number one. I was also interested to see that 
