On many intl flights out of jfk, over the last 5 months, i've noticed tsa agents at the gate doing random screenings. I guess tsa doesn't trust (1) their intial screenings and/or (2) vendors at the airport--haven't you noticed the shelf of time-bombs

at most of the newsstands? [a la the movie
airplane.]
You bring up a great point here!! If the TSA is the do-all, be-all, end-all of screening accuracy and efficiency, WHY IS THERE A NEED for gate screenings? Al this means is that thy know their security checkpoints are bulls**t.
Also, being on a cell phone call (or at least having a phone to your ear) is great way to avoid the inane SPOTter's questions. All I usually get is "how are you today" to which I respond "I'm going to work, so it sucks" and that's usually all they need to hear. Once I got "where are you traveling to today" and I poinhtd to the boarding pass and said "Well according to this, P-D-X. Did you know something about my flight that I don't?"
When they turned down my ex-air force, 17 year police veteran father-in-law for a TSO position claiming he "did not meet their requirements" I lost any respect I might have had for the TSA---whcih was none to begin with. He has a good time pointing out to these clowns at least three things they missed that are real, genuine security concerns every time he goes through their checkpoints.
So it actually makes a lot of sense that they feel the need to re-screen people at the gate. Their system is a joke.
--PP