n many cases that is impossible to many users. And the door lock analogy does not easily apply. You don't know where the door lock is, expecially with open and public systems in the same area. For example. Setting in my office I see 7 open wi-fi networks. One labled bob. How the heck do I know what or where bob is? He could be a mile away or setting in a car. Another one says something like rt01cityname. What is that? Is it a free public access point? The answer is unclear.
It's real simple. If you don't know whether or not you are authorized to use a network resource, any type of resource, don't use it. It is up to the user to make sure that they are authorized to do something. And if they are not, they are liable for their actions.

How many people here think it is perfectly legal to walk into a public place of business, and hook their laptop into the rj45 connection sitting behind the water cooler? It may not get you arrested, but as soon as somebody in that office sees you sitting on the floor with your laptop hooked up to the wall they are going to ask you what you are doing. Same thing applies. There is no sign that specifically says you don't have the right to use this, but there is nothing that would give you the impression that you have the right to use it. In some cases, you probably would get arrested depending on how the office workers wanted to treat you.

People want to make a distinction just because this is transmitted through the air, and that distinction just doesn't exist. A network device is a network device, if you are not authorized to use it, using it is illegal.

I don't know if I totally agree with Negatives analysis of the issue as ignorance does not excuse anybody from the law. The prosecutors may not choose to prosecute you if they think you meant to connect to another machine, but the act itself it still technically illegal.

Most people may not realize this, but plugging your laptop into a wall socket in a public place is also illegal. People were getting arrested for this frequently several years ago. It doesn't matter that there was not a sign saying you can't use it, or that there was no security measures in place to keep people from using them.

That I'm aware of New Hampshire is the only state that has taken an official by passing a law stating that unsecured network operators cannot prosecute people who use their networks- http://www.gencourt.state.nh.us/legi...03/HB0495.html

More legal items to read, written by lawyers and quoting the FBI and other federal laws-
http://www.vjolt.net/vol9/issue3/v9i3_a07-Ryan.pdf

Specifically it notes this memo published by the FBI. "Identifying the presence of a wireless network may not be a criminal violation, however, there may be criminal violations if the network is actually accessed including theft of services, interception of communications, misuse of computing resources, up to and including violations of the Federal Computer Fraud and Abuse Statute, Theft of Trade Secrets, and other federal violations"

Note that this journal entry draws a fine line about what is considered intent. It could be argued that by telling your wireless NIC to connect to a wireless network that you intentionally meant to connect to that network. The law is pretty clear, how it is applied is what is not clear.