Ok guys, I came across this a bit differently - I just wanted the wiki page for the show(which doesn't exist yet).
The show is obviously fake from the beginning, thanks to the opening sequence - "A secret room is found containing...blah blah blah... Dark Secrets!"
The backstory of the show is easy to grasp - the hidden room that is found contains all this information - interview recordings, police documents, pictures, etc... and then from all that, the producers of the show put together "Dark Secrets." The interviews, recordings, pictures, all that is quite old - my best guess is several decades based on the equipment shown - such as the quite old recordings device that is often shown while the narrator AKA The Detective is talking.
The Detective, as I like to call him, is the guy who has put together all this stuff. He is not one of the show producers (also, please keep in mind that this is all fiction and I'm just telling you the backstory of the show). He did all this quite some number of years ago - THAT IS WHY THE VIETNAM VETS ARE SO YOUNG. While the show producers are showing the show now, the actual recordings of the interviews and whatnot are done by the Detective quite some number of years ago - that episodes case, soon after the Vietnam War.
I believe, as part of the backstory of the show, the show itself only provides the reenactments. IE, the scenes where the due is beating the heads in of the Viets, or when the old dude and his wife are sitting in their house and he tells his wife that he needs to take a crap. It would be kind of hard for a guy in a basement to get footage of that, so I'm assuming that we're not supposed to think it was provided by the Detective.
So, three things to keep in mind while watching the show to enjoy it:
1) It is completely fiction
2) The Detective did not produce all this for the TV show - the producers of the TV show stumbled upon his work and used it to make the TV show (That's the fictional backstory).
3) The Detective did all his work (interviews, recordings, detective work, etc...) DECADES AGO. Between the 1960's and the late 1990's, it seems like.
It seems like so many people get angry/annoyed at this show simply because they can't grasp it. Some people get angry because they think it's real and then find out it's fiction and feel lied to. Others get angry because they think there's inconsistencies (and yes, there are a few, but most of them that get called out aren't really inconsistencies... an example being the Vietnam episode).
So please, go back and re-watch - pay attention to the opening sequence (it'll be the part towards the front of the show where a guy with a completely different and younger-sounding voice explains the shows premise about finding a secret room full of all the documentary stuff). You'll enjoy it so much more then.