Wireless network security

Bruce Schneier, a well known expert on security and applied cryptography, writes an interesting blog called Schneier on Security. Recently he wrote a post on his open wireless network. That's very interesting! Here's a security guru and he's arguing that you should not secure your wireless network (even though he agrees that the WPA protocol is very good):

To me, it's basic politeness. Providing internet access to guests is kind of like providing heat and electricity, or a hot cup of tea. But to some observers, it's both wrong and dangerous.

Schneier is unmoved by concerns that strangers might use his open wireless network to indulge in various criminal, or at least unseemly, activities. More interestingly (to me at least):

I'm also unmoved by those who say I'm putting my own data at risk, because hackers might park in front of my house, log on to my open network and eavesdrop on my internet traffic or break into my computers.

And why is he unmoved? It's because:

...my computers are much more at risk when I use them on wireless networks in airports, coffee shops and other public places. If I configure my computer to be secure regardless of the network it's on, then it simply doesn't matter.

And this is essentially the policy I've followed---almost. I dont' encrypt by wireless network. Instead, I depend on the firewall running on our Macs to protect us from prying eyes (if there are any). And I'm assuming that any eavesdroppers on our Internet traffic won't see anything sensitive---if it's sensitive then it had better be going over https, for otherwise there are plenty of other points on the Internet where plaintext passwords and such can be intercepted.

However, I have enabled Mac address filtering, but that doesn't really protect you from a determined hacker. I guess I don't quite agree with Schneier's "basic politeness" argument above.

Talking about open wireless networks, when I was in India in December I found an open wireless network at my parents' house (my parents don't have Internet access). So I used it to quickly read my email. But later my sister told me that in India Internet access is paid for by the megabyte downloaded...! So, unlike in the US, my use of the open wireless network really did amount to "stealing" from my parents' neighbor...:-( After that, I wasn't too keen on using the open network.