1. It’s Trespassing.
2. It’s Stealing Bandwidth
It’s no different than someone coming over the border illegally.
He parked in a public parking lot so it's not trespassing. They didn't password protect their network and they broadcasted the signal beyond their store. Outside the store was a sign that simply said "FREE WI-FI". It didn't say anything about buying anything first. The store is to blame and this guy got screwed because of a lousy law. There was a CNN video about this last week, but I can't seem to find it now.
You are correct. Some people are just “jack booted thugs” at heart or just too stupid to understand a few basic facts.