A poster on NEDoD just pointed out an obvious-in-retrospect weakness in the TSA airort security screenings:
ObTerroristThreat: If my name were Mohammed and I wanted to send another message to Mr. Bush, I'd get 20 friends, send each one to a different major US airport, and let them blow themselves up while in the crowd of 200 people waiting to get through the TSA security check. That would a) scare the bejeezus out of the ninnies, and b) really stump the TSA people as to how to check for terrorist before you check for terrorists.
All together now: "Hmmmm." Of course, you have to get your 20 terrorists into the country first; but does anyone really believe al-Qaeda, Hamas, or Hezballah (or whatever the currently-fashionable spelling is) can't do that?