Technically, the network isn't leaking anything. To access the network, you have to send signals yourself to carry on a two-way conversation with that network. Nothing is being "thrown away". That argument is even less valid that similiar arguments about stealing power "through the air".

While it would take a lot of rambling to explain the details, if you have a long stretch of property (we're talking a couple miles) it is possible to capacitively couple with a HV transmission line and steal power. It's been done and there have been court cases where the argument was the power company is leaking their field all over adjacent property and if they don't want someone to make use of it, they better shield it.

The courts did not buy that argument. The physics of that argument don't even hold up. Power lines don't radiate energy, save for a tiny little bit that is insignificant. If it were easy to radiate 60Hz, power lines wouldn't be very efficient as you'd be wasting wads of what you were trying to transmit. They do have an extended EM field around them, but that is not a radiation field. When one capacitively couples to that field, one *alters that field* to pull energy from the line. One is actively changing the system to cause it to transfer power.

Many people don't understand this, even those who should. One big scare tactic with HV power lines is to hold long fluorescent tubes under them and demonstrate a glow. Some of the big ones will do that. The claim is then that energy is leaking out, and just imagine what it will do to a human body etc. Well, the same principle applies. The tube is coupling to the ambient field and pulling energy out that wouldn't otherwise leak.

And likewise, when one accesses a wireless network, one is very actively altering the field so to speak by sending your own signals to cause the network to give you access and transfer your information back and forth.

Now where I would draw the line is with true leaks. That is, if you're just passively listening to things actually radiated, thrown away, then I don't hold that as theft or eavesdropping. But the law sees that differently, I think as well.

-Richard