SSSS! Behold the four letters that you don’t ever want to see on your boarding pass. If you find the Secondary Security Screening Selection — SSSS stamp on your ticket, you should know that the TSA agents will be treating you to an extra-special and in-depth security screening.
But how, and by whom, are passengers selected for this additional form of screening? After Jo Freeman’s recent unpleasant close encounter of the TSA kind, she wants to know. “What you need to know about that SSSS stamp on your boarding pass”