Warchalking

I don't even see the argument. If you're using bandwidth that you're not paying for, you are stealing, plain and simple. If I ran a wireless network that was running a little sluggish, then took a walk outside only to find volumes of little chalk glyphs scribbled all over my building/campus, I'd be pissed as hell! Every jerk with a PDA would be stealing the bandwidth I paid for. Quite frankly, I'm surprised that we don't see more signs like:

This area is frequently patrolled for bandwidth hijackers.
Violators will be shot on sight.
Have a nice day.

As for the notion that scribbling those glyphs on the ground should be illegal...I agree! It's like writing the combination of someone's safe on a sticky note stuck to the dial. Sure, people don't have to take advantage of it, but you just facilitated someone who does. Aiding anyone in committing a crime is a crime. Sorry.