Now here is my question. Why is this "stealing wifi," as some folk say? You, the owner of the hotspot, have chosen to attach a device to your network and -- very rudely in my opinion -- blast it at maximum volume to the world. You also decide to keep you system open, rather than closed, creating the impression that you actually _want_ to have people use your hot spot. Simplistic analogies to "if I leave the door open to my house blah blah" don't cut it, because this is not how this stuff works in the real world. There is no physical intrusion, and there are people who blast open networks at maximum volume to facilitate public sharing (I know many in the community wireless movement). To the extent there is an analogy to the physical world, it is more like your apple tree overhangs my property and the street. So I decide to pluck off the ripe apples on my property and eat them, as do folks in the public thoroughfare. Common law has long established that your intrusive apple tree is tresspasing on my property and I can eat the apples. I am not an apple thief; my neighbor is a tresspassing nuisance.
If anything, it is the hotspot operator who is tresspassing into my apartment/house/public thoroughfare, and at a cost to me. My thoughtless neighbor "Mr. Lynksis" confuses my machines that do ad hoc networking by automaticly grabbing the strongest open signal. So not only am I "tresspassing" without my knowledge, but Mr. Lynksis is extruding into MY airpsace and disrupting my home network. I can adjust my network settings to ignore Mr. Lynksis, but why does Mr. Mr. Lynksis the thoughtless neighbor get the free ride presumption? Why don't I get to assume that if Mr. Lynksis is blasting into my apartment or my street, he WANTS me to share. Because if he didn't want me to sahre, he'd change the blasted default power settings or at least set a blinking password.
Mr. Lynksis and his thoughtless buddies also impose a cost for me in network response time. If he is intruding into "my" airspace, then my 802.11 device may experience slow downs due to congestion. Why should I protect Mr. Lyknsis' airspace when he imposes a cost on me?
By contrast, consider the positive benefits of establishing the opposite presumption. Suppose the law establishes that anyone running an open network that can be received outside the hot spot operator's private premises is explicitly inviting use by anyone able to receive the signal using a standard receiver (we will exclude the hot spot owner trying to maintain a proper power level but who "leaks" because I am actively using a sensitive receiver). This creates incentive for hot spot operators to manage their networks efficiently, creating positive externalities. It also allows those in the community wireless movement who actually _wish_ to use offer an open access point to do so, and facilitates use of that open access point.
There is no a priori reason why we can't create laws that require responsible network management, and a number of reasons we should. The primary driver for establishing the "tresspass" rather "public nuisance" presumption seems to flow from ignorant analogies to private property and a deliberate ignorance in refusing to read the bleading manual. I see no reason to reward such ignorance. Alas, as a fair number of judges and legislators fall into the ignorance catagory, we end up with presumptions that reward ignorance and encourage inefficiency.