Fortunately, the TSA and airport screening is pretty irrelevant in the overall counterterrorism effort. It's very effective at security theater, which keeps Congress, the media, and a large percentage of the American public happy and "feeling safe." The only things that happens at an airport checkpoints are:

1. Catching the amateurs, defined as the guy who forgot he had a gun in his carry-on;
2. Catching common criminals using the cover of an "administrative search".
3. Taking on the mission of human trafficking by demanding that little kids state their names in front of their parents at the ID checker interrogation.