That`s a lot of BS (on behalf of Airport Security). It hardly serves the purpose of keeping terrorists off of airports by not challenging someone right when the violation is observed. The security agent should have asked the person-- "stop-- where is your pass?" If he would have been unable to produce it, it`s time to arrest the individual and question him later. I`m sure that would do a lot more for airport security than underhanded, sneaky and backstabing techniques like not saying anything at the moment but sending him a letter a few days later.