Hot air balloons flying over a densely populated area could also wreck havoc by air dispersion of chemical, biological or nerve agents. A crop dusting plane could dispense the same agents over a sports stadium with deadly results. It starts with poor/weak immigration enforcement. Political correctness will bring us down / is bringing us down as a country. I often travel by rail, logging over 12,000 miles in the last 2 years, out of frustration with dealing with TSA agents. I have flown a few times over the same time span, despising even more the brown shirts and their inspections with as much enmity as is humanly possible.
Oh boy, here come the backpatters.