One security measure I would welcome is having a small electronic signature stand, similar to that used for credit card transactions at sears, home depot and others - which requires a signature, which can be matched with on record rather quickly.

Of course, some of us would have to clean up our act, but the time between taking the signature, and boarding, could be made sufficent.

The reason this is useful is the clear evidence that many of the peope involved in the attack used assumed or fictious identities. The signature match would deter some, catch some, and, in the event of a failure - make tracking those on board easier.

We already do it when we buy a box of screws, so there is no incremental loss of privacy above what we already have. If you want to go from place to place anonymously, drive with a tinted windshield and don't speed.