Er....How do you know when the real thing comes along?
Ignoring suspicious people? This same tactic could have been used at the Towers Attack - then how would officials feel?
Frankly, I expect people to do their jobs and report suspicious behavior as the president requested. To ignore anything is setting us up for another attack and plays right into the hands of the terrorists. So what if it is a false alarm - at least we got practice in spotting suspicious people, corralling them, identifying, and investigating suspicious actions.
Next to the Russians we are probably one of the most paranoid societies on the planet. I am a little afraid of a knee jerk reaction, but I'm sure we will work it out. We are now in a different time. We must be defensive and offensive at the same time. That is what war is all about.