Our reality could very well be an illusion that they can manipulate at will. That's probably why you can't find things about events that you could have sworn happened or how there is always a convenient excuse or piece of evidence that magically spawns that debunks a conspiracy when it gets too big. The roswell alien interview tapes talk about the mind matrix and false memories that are injected to the lifeforms living on this planet. It's very possible some demons have lived for millennia and are currently "humans" now with made up history and background.