[9][3] In 1993, Greer founded the Disclosure Project, the goal of which is to publicly disclose the government's alleged knowledge of UFOs, extraterrestrial intelligence, and advanced energy and propulsion systems.

[10][11][12] Greer describes the Disclosure Project as an effort to grant amnesty to government whistleblowers willing to violate their security oaths by sharing classified information about UFOs.

[6][15][16][17][18][19] In 2013, Greer co-produced Sirius, a documentary detailing his work and hypotheses regarding extraterrestrial life, government cover-ups and close encounters of the fifth kind.

[20] The film was directed by Amardeep Kaleka and narrated by Thomas Jane, and covers Greer's 2006 book Hidden Truth, Forbidden Knowledge.

"[26] Critic Noel Murray reported in the Los Angeles Times that the film was "overlong and rambling – more concerned with disconnected anecdotes than making a compelling case or telling an interesting story.

"[27] John Defore of The Hollywood Reporter wrote that the film "is far too impassioned in its nuttiness to be a purely cynical, Scientology-style sham", that it "rather strangely squeezes the last few years of UFO-related news coverage into a misleading frame, arguing that journalists, pundits and the government are collaborating to build fear in the public that would justify the establishment of a 'one-world government' that could wage an 'interplanetary war'", and notes that "though [Greer's] been summoning [UFOs] from across the galaxy for decades, he can never convince an alien ship to travel an extra couple of miles and hover for a good photograph.