Padawan said:
It's obvious that they aren't intending to share their network with anyone, and I would effectively be "stealing" the bandwidth that they themselves are paying for. I really don't see that as being different from any other form of theft. Some might use the argument that, "They didn't protect the network, so it's okay for me to use it", but I don't feel that's a valid point. If it were, the same people arguing it would then have to agree that it would be okay for a thief to steal from their house just because they left the door unlocked while they were away. In either situation, the owner may have used poor judgment or been naive, but that shouldn't be considered justification for theft.
A better argument would be: They left their groceries in my kitchen (or garage or Yard etc), so it it illegal, or immoral, for me to eat their food? Entering a residence or vehicle that is not your own without the consent of the owner or a court, regardless of it being locked or not, is a crime. However in this case, you don't need to leave you own home or enter/break into anything.
The real argument here is centers around the fact that you don't need to leave your own home or in some cases do
anything illegal to be caught in the quandary. Is the burden of responsibility on the user or the owner of the wireless signal? More and More ISPs (mine included) are placing the legal burden on the owner (subscriber) to ensure that a network is locked down. While legal precedence has been set in regards to continued abuse of personal or business networks, all of the cases consisted of individuals who were "war-driving", the most recent involving a Starbucks I believe. None, that I am aware of, have involved a person sitting in their own home.
Both the legality and morality of this subject are open for debate.