To walk through an airport with Bruce Schneier is to see how much change a trillion dollars can wreak. So much inconvenience for so little benefit at such a staggering cost. And directed against a threat that, by any objective standard, is quite modest.
Some other important quotations:
The full-body-scanner program—some 1,800 scanners operating in every airport in the country—was launched in response to the “underwear bomber” incident on Christmas Day in 2009, when a Nigerian Muslim hid the plastic explosive petn in his briefs and tried to detonate it on a flight from Amsterdam to Detroit. It has an annual price tag of $1.2 billion. The scanners cannot detect petn directly; instead they look for suspicious bulges under clothing. Because petn is a Silly Putty–like material, it can be fashioned into a thin pancake. Taped flat to the stomach, the pancake is invisible to scanning machines.
Even if the T.S.A. were somehow to make airports impregnable, this would simply divert terrorists to other, less heavily defended targets—shopping malls, movie theaters, churches, stadiums, museums. The terrorist’s goal isn’t to attack an airplane specifically; it’s to sow terror generally.
Read the entire article; it’s worth your time.
Bruce Schneier is a cryptographer and security expert who blogs here.