I reckon half the problem is Bl**&y Awful Airports total failure to provide enough security staff and machines, thus leading to long queues. I don't know how much they get per passenger to cover 'security', but it wouldn't surprise me to find that if you dug deep enough into the accounts, you'd find they made a profit because of their parsimony. The TSA at Phoenix the last time I went through, had a line moving so quickly you didn't have time to put your bag on the ground before you were moving! Compare with the so called 'fast track' at T4 last Monday - 13 minutes.