Don't neglect the people who are not mentally ill, but still can't tell the difference between "Yeah, we've got a lot of data on UFOs (stuff we couldn't accurately ID for a variety of reasons) that's classified (because some of it legitimately need to be secret, and we over-classify a lot)" with ""Yeah, we've got a lot of data on UFOs (little green men in flying saucers) that's classified (because we're part of a conspiracy hiding the existence of intelligent alien life)".
And the people who are not mentally ill who think that being an authority on the US's UFO programmes is a nice retirement gig that comes with none of the downsides of actual whistleblowing...