I did a post at the beginning of the month called Home wireless networks: Why is everyone still only using WEP? I suggested if you hadn't done it already, you should secure your wireless network. I also suggested that if you were already secure using WEP, to update that to WPA...it's better. Since then I've found several interesting articles that talk about 'stealing" Internet access on unsecured wireless networks and the legal consequences.
This article on money.cnn.com talks about Stealing your neighbor's Net. Depending on where you live there are already laws that make this illegal. There have already been several cases go through the legal system, as an example take a look at this article about a Man charged with wireless trespassing. He was parked outside someones house piggybacking. Those of you that haven't heard of piggybacking, this is what they do.
Unauthorized access to the wireless network, while not illegal everywhere, surely is at a minimum unethical. Wireless access is not free everywhere, and much as I'd like to see ubiquitous FREE wireless access, until that happens SOMEONE is paying for it. Even if you can connect, that doesn't mean you should. It would be like going into a candy store when no one is behind the counter and taking stuff without paying. Sure, you say, but that's not the same. Of course it is. You're taking something you haven't paid and isn't yours, in this case access to a service. (I'm sure that will get some responses). Even in the gray areas, like sitting outside a hotel that you're not staying at and using their free wireless, its still wrong.
Another, slightly related, issue I came across is highlighted in this article, Airport warning: Fake wireless networks steal users' information. Since I've been in most major airports on the eastern seaboard I see this all the time. I'm sure a lot of people get suckered into connecting to the bogus network and providing information. I'm so paranoid now that I check the certificate on the hotspot website before I even enter my username and password for my hotspot provider.