Wireless Hackers Leave No Tracks

Computerworld - I'm a parasite. I didn't pay for the bandwidth I'm using right now. I didn't ask for permission to use it -- I don't even know whom to ask. But I'm on holiday, I have a few bits of work to finish up before I can relax, and I need to send my e-mail.
The broadband service in the rented house doesn't work, so I stuck in my wireless LAN card and found two WLANs covering the house. One has a Secure Set Identifier of "lopez" and has Wired Equivalent Privacy turned on; the other has an SSID of "default" and no WEP.
My wireless card has automatically associated with the "default" base station, which gave me a Dynamic Host Configuration Protocol address. Now I'm connected to the Internet at 11Mbit/sec. with no fee and no restrictions on what I can do.
When WLANs hit the mainstream a few years ago, the security focus was on confidentiality, and vendors included WEP to encrypt data in the air. WEP has flaws -- it might not stop a snooper in your parking from reading your data -- but just the fact that "lopez" had it turned on was enough to turn my attention elsewhere. Why hack "lopez" when "default" is sending in the clear?
But having data sniffed from the air isn't the real threat that wireless poses. That problem is easily solved by using cryptography. A bigger worry is "de-perimeterization," which is a fancy way of saying that the walls of the normal fortress model are falling away, thanks in part to wireless. In the good old days, you inventoried all external connections and put firewalls in front of them. Now, nearly every organization has so many connections to the outside that it isn't feasible to set up firewalls to control access to all of them. If your wireless users need access to all of the internal services, what can you block with a firewall?
And if you're a hacker, why bother trying to intercept data from the traffic flying about when you can just connect to the network and pretend to be a legitimate client? Once you become a full node on the network, you don't have to wait for a client to connect to download the information you want and sniff it. Instead, you can just waltz right in and take what you want. This is a lot less covert, but unless the target has a hair-trigger intrusion-detection system configuration and very good triangulation equipment, you probably won't be discovered.