re: What is it about these hats?
Yep, in the '70s I worked with a draftsman who wore a tinfoil cap. It was quietly explained to me that he believed that the CIA was trying to beam thoughts into his head, thus he wore the basically Cargo Cult Faraday cage and insisted on having his drafting table located away from windows.
I was also informed, in a general way, that the man had in fact worked on top-secret projects, and suffered some unspecified trauma. This was highly credible considering the company and its work, and the actual connections of some key people to the dark world. I think it was a case of "old hands" in the secret technology world taking care of one of their own who'd been wounded in action.