"Plots carry their own logic" - Don Delillo
Conspiracy theories are our modern day folk stories. They come in and out of vogue, but they never, ever truly go away. For every weird, outlandish story, there is some element of truth which is enough to sustain them for years, decades & even centuries. The core of all of these stories is secret plans within plans or secret secrets. The rabbit holes go deep, split off and divide into so many if you try to follow them all, you might as well put on the mercury coated hat and be done with it.
Ah, but just like these stories, I digress. So if you want a rear paranoid film which will make you deactivate you phone's GPS & re-watch Loose Change, why not go with one from the 70s. It has has it all: unmarked military helicopters, murdered whistle blowers, fake space exploration & (it doesn't get any more meta than this this) OJ Simpson. Pull the shades, lock your doors & windows, put a towel under the door and smoke that joint. Enjoy because it's just a movie, right?