[Edi]

More or less.

If they're getting ot for free without asking for permission or checking that it really is meant to be used by all and sundry without conditions, then yes. If they check that it's okay or fulfill the conditions (e.g. buying that cup of coffee anbd thus becoming a paying customer), then no foul.

WLANs are a fairly new phenomenon, which is why there is so much ignorance about them and the laws governing them, but existing laws pretty much have it covered in most places if you just apply the same principles. Due to this fact, I'd have been inclined to let this guy off with a warning, had I been that prosecutor and had leeway. He was obviously harmless, and it isn't exactly the most ethical thing to make an example of him this way when the consequences of having a felony conviction can be as severe as they are in the US (somewhat depending on location, of course).

On the other hand, it is becoming more and more common for e.g. pedophiles leaving their WLANs unsecured, so if their activities are uncovered, they can try to weasel out of trouble by claiming that they had no idea someone else was using their WLAN to surf for child porn, for example. There have actually been at least two court cases like this in the US that I know of and fortunately in both of them the perverts got themselves a judge's gavel square on the forehead. Of course, in both cases there was other physical evidence besides the ISP access logs that indicated the WLANs in question being the source of suspicious activity. I could probably come up with more creative excuses to get off the hook for various other sorts of things regarding WLANs if I were of a mind to put effort into it, so being too lenient is not a realistic option.

Telecommunications security and confidentiality are thorny topics, as is their relation to civil rights and how far in what directions you can go. It's a fine line to walk and sometimes the outcomes are less than optimal, like in this case. But given the maximum possible penalty, the man can count himself lucky to have been let off lightly. Had he actually been guilty of more than a stupid, thoughtless mistake, the outcome would have been VERY different, if my grasp of the practical side of the American system is anywhere near accurate.

I hope that helps you understand why I took the tack I took. Having studied the field as a major subject, having a vocational degree in IT and telecom stuff and working at an ISP, I've had occasion to keep an interest in the subject and to actually know about it, because if I screw up and step on the wrong side of that divide at work, I'll get a bootprint on my backside. That's a fairly strong motivation.