For all the conspiracy theorists....
..here is some info:
"Eyes Wide Shut is a 1999 erotic thriller film loosely based upon Arthur Schnitzler's 1926 novella Traumnovelle (Dream Story). The book deals with the thoughts and psychological transformations of Doctor Fridolin over a two-day period after his wife confesses having had sexual fantasies involving another man. In this short time, he meets many people who give clues to the world Schnitzler creates. This culminates in the masquerade ball, a wondrous event of masked individualism, sex, and danger for Fridolin as the outsider."
There is an Austrian movie from 1969 (the Moon ladning!!!!?!?) which is quite identical to EWS. You can watch it here - https://www.youtube.com/watch?v=inJp4rPyLrU (skip to 39:00 for the good stuff).
I think Kubrick liked the story and simply remade it with bigger budget. And the movie is not about exposing secret society and their rituals. It's about the inner journey of the main character.