When I think of the Public Zone, two things immediately spring to mind ”surveillance and the looming potential for catastrophe. I'm not just talking about the threat of terrorism. A couple of recent public catastrophes were the fire at The Station nightclub in Rhode Island that killed 96 people and injured hundreds more, and the stampede at the E2 disco in Chicago that crushed 21 club-goers to death the same week; neither of these was caused by terrorism. This leads me to the first rule of avoiding public catastrophe.
Whenever you're in public, and this includes the common areas of your own apartment building, devise a vigilant exit strategy for common worst-case scenarios ”fires, earthquakes, floods, explosions, and random acts of violence. The first thing to do when you're at your workplace, the movies, a mall, a stadium, a nightclub, a restaurant, an airport, or when you board an airplane is to check the location of the exits and figure out how to reach them in case of an emergency!