The reason for this is the expansion of the TSA (or airport security body). When you have a very small number of people/devices, you just let people in. When yo

The reason for this is the expansion of the TSA (or airport security body). When you have a very small number of people/devices, you just let people in. When you have a large apparatus, you make use of it. And the large apparatus will try to find work for itself by stopping as many people as humanly possible. They'll also stop the most normal people out-there because they tend to make less of a fuss about it. Recently, I flew SFO and they seemed to have a shortage of TSA officers or something (all security booths were empty). There were a couple old guys, they just randomly selected people for screening but everyone else were just let go without baggage screening.