I had it happen not too long ago in Cleveland. I dropped my keys as I was getting in line. A TSA agent snapped at me for "not looking after my belongings" as I bent down to pick them up. Then I lost my usual calm demeanor and started trembling. As I got in the MMW scanner, the agent said, "Jesus Christ, stop shaking!" I would have liked to have turned him in, but I wanted to get as far away from that checkpoint as possible to collect myself.
Looking back, it wasn't really a pathological panic attack. I was being attacked in a verbal and psychological sense. My own visible anxiety was a normal, adaptive, human response.
There are so many reasons why the TSA consciously or subconsciously elicits anxiety. There are crowds of other passengers, so there is already a sense of claustrophobia and social anxiety. Many of the staff can be rude, demeaning, and inappropriate. There is the sense of being judged "guilty until proven innocent." And there are many metaphors to the Holocaust: guards talking about "selectees," a guard deciding "which line" to will be sent, and involuntary radiation and immodesty.
In other words, a "panic" response is actually normal.
Preventing this reaction is difficult. It requires a lot of work. I drug myself with benzodiazepines, which sort of helps. I choose lines carefully, and verify tsastatus.net. I also do whatever I can to distract myself: think of a song, a movie plot, anything I can think through in my head. If there are cute babies in the line, I always stop and say hello. I'll still be profoundly anxious, but these measures help.
I can't not fly (Sorry about the double negative.) So I work to tell myself, "I speak up, I write to the legislators, written an op-ed in the newspaper, but I also recognize that I cannot control the TSA. I have to deal with some form of acceptance."
I made the mistake of talking with a shrink about it. He gave me an, "anything for security" response, and talked about how grateful he was to be pulled out of line and get frisked in public. This is not a man I would trust.
Somehow, somewhere, I dream that there are TSA administrators and staff with compassion, who realize that they are inflicting an undue level of stress and suffering to many. I like to think that just one staff member or official recognizes that the TSA's behavior is damaging and painful.