Here's a question: if you identify a person for additional screening based on their behavior, can/will you tell the passenger why? Would you volunteer that information or wait for the passenger to ask?
And how specific can you be? Would you tell him, "You're wearing a heavy coat in September, sir," or would you say something generic like "Your behavior has led me to believe a secondary screening will be necessary."
We are specifically forbidden from telling passengers about behaviors which caused them to be referred for additional screening. It is carefully protected SSI, and (supposedly) could be used to beat the system. In this area, I disagree with the powers that be in Virginia, but I am very limited in what I can actually do about this. The press releases and fluff news stories seem to include a lot of this information, however. I'm not sure how it is less of a problem when reported in major media outlets.