Apologize if the posts have moved on from the flashlight analogy, as I see people are discussing this issue in more technical terms (Iball, where do you even get those law posts?)

However, I just wanted to give my 2 cents on unauthorized Wifi usage as being an extremely minor offence (i'm just assuming email checking, like what the UK guy was arrested for, and not hacking or torrents/illegal downloads), that you could argue the following:

1. Intensity of the intrusion is low
In the flashlight example (one neighbor turns on this light inside his house, the glow outside akin to Wifi, and another flashes one a flashlight into the Wifi owner's house, akin to accessing the Wifi by sending a Wifi signal from his wifi adapter), this 2 way communication has very similar levels of intensity, and if the flashlight is flashed into someones eyes, or invokes suspicious behavior, I can see how this is not acceptable.
However in actuality, Wifi access (for emails) accesses a very small amount of bandwidth (negligible in some cases if the access line >3Mbps), which we cannot say its hardly causing any trauma. I liken this 2 way communication like an echo of a radio blaring, which the radio sound returns back to the radio owner at a fraction of the original amplitude.

2. Wifi connections extend beyond the owner's property
Analogies of leaving the door open and stealing a TV in an extreme exaggeration compared to an actual wifi access. Again, wifi access is a transfer of Ghz waves that does not cause monetary damage, and does not include actual trespassing. If we really wanted to use an analogy (which does not really illustrate a wifi access, but shows no trespassing), lets say that if you found a penny in the street, would it be okay for you to pocket it?

I think lets get away from using analogies and stick to the actual wifi access, as analogies tend to over simplify, leading to exaggeration of the actual issue.