I think as long as Americans maintain a "zero tolerance" posture towards terrorism, this kind of security will always be justifiable, because the goal is zero e

I think as long as Americans maintain a "zero tolerance" posture towards terrorism, this kind of security will always be justifiable, because the goal is zero events, versus accepting that some percentage "will happen." Nuclear terrorism is example #1 of why "by any means necessary" is considered appropriate for surveillance. Since it's hard to argue this will "never" happen, well, it justifies a lot. Whether that is right or wrong, I still don't know.