When he goes someplace he blocks of a 30 mile radius around him. In Palm beach that blocks off the whole coast where all light airplane traffic transits. Folks down there are not so used to Presidential no fly zones. There will be more. Ridiculous waste of airspace knee jerk reaction to 9/11.
Plus fewer and fewer pilots call up a briefer before launching - with GPS and on board weather and flying VFR... what's the point?
Ergo, those who do not otherwise pay attention to the world and going about their merry way, are getting the surprise of their life when an F-16 sidles up alongside... Oops!