BleepingComputer.com: Security Risks Of Wireless?

My father, who has gotten a new laptop, was wondering about the security risks of having a wireless modem (his words) on it. He was using it in a cafe when it notified him that it had found a wireless network, which has gotten him kinda spooked. He isn't using the wireless capabilities of the laptop; all networking is done through cables. So he asked me what the security risks were, and if it is possible to hack the machine trough it. Me, never having had anything to do with wireless networking, thought I should ask the experts before giving any recommendations.

One of the major security risks of using wireless is that unless you have an encrypted connection everything you send to and from your computer is sent in plain text. Which means if you send your password: cat568 across the wireless network, someone with a program called "Etheral" can pick it up exactly as "cat568." However if it were encrypted it would appear a little more random.

Another security risk is that someone can send packets to your comptuer than can do damage. Like packets that would seek out data on the network, or to find information that is on the computer and send it to the remote computer. I would strongly advise anyone using a wireless card to use a very effective firewall.

Also another problem with wireless (not really a security issue) is that when you have multiple machines connect to one spot you all are sharing bandwidth, even it were not connected to the internet.

A couple of good resources for wireless security:

WPA Wireless Security for Home Networks

Intel's Wireless Security Network Resource Center