Ultimately airport security is a joke and complete WINDOW DRESSING. It is not in the least bit effective. Security checkpoints are there to make Granny flying once a year or so feel safe as she can actually SEE them doing something..
At the airport I work at, Security representatives (I wont call them "officers" as that implies a reasonable amount of training and expertise, let alone professionalism) ask you (staff at the staff channel) if they can inspect items at random (radio, jacket, folder, rucksack etc). This is not done for the sake of random inspections to thwart terrorist plots, to keep themselves and there procedures non-routine and unpredictable. No, this is done because the government has set them TARGETS of a certain number of items that they have to look at each bloody hour! They pick up a radio adn look at it in the most cursory way and say to there mate with the tally shhet "One radio..." They never look to see if it actually WORKS. For all they know it could be a bloody empty plastic case filled with semtex!