This is a bizarre division of labor. You carefully pack to avoid any liquids more than three ounces. You stand in a security line. You take off your shoes. You get your fingernail clippers confiscated. You run your carry-on bags through an X-ray machine and walk through a metal detector, with an extra wanding if your spare pocket change sets off the alarm. And after all that, it’s still your responsibility to subdue the terrorist in the next row trying to set off the pentaerythritol tetranitrate (PETN) secreted on his body.