What made me start thinking about these fake documentaries was a new show I discovered called Lost Tapes on Animal Planet. It's been around for a few years, but I only came across it this week. It's a fictional show shot in the shaky camera, low budget style of some reality shows. The acting is bad and the point-of-view videography is inconsistent, but it's still more entertaining than some of the real documentaries out there that hunt for cryptozoological creatures, such as Bigfoot or the Loch Ness Monster. Those authentic programs tend to be rather boring, in my opinion, because they find nothing. Lost Tapes, even in its cheesy, sometimes amateurish methods, presents some cool moments. The episodes I've seen so far include "Reptilian" about a subterranean rave party scene where young people start vanishing thanks to shapeshifting lizard aliens, and "Wendigo: American Cannibal," which was an obvious Blair Witch ripoff but had a couple of effective moments.
The movie mockumentaries have been the best so far: Cloverfield about a giant monster attack, Paranormal Activity about a haunted home, and The Last Exorcism about a disillusioned evangelical minister who ends up fighting the Devil to save a possessed girl. All those plots have been done before and arguably much better, but by filming them in a "found footage" manner, pretending it's real rather than a fictional movie, adds a fresh angle. It's a gimmick that can grow old quickly and can fail if not executed properly since by its nature it draws attention to itself and its cinematography, but Blair Witch proved that it can work extremely well, presenting a lingering atmospheric effect that stays with the moviegoer long after the final credits roll.
The Blair Witch Project didn't invent the genre. Cannibal Holocaust was a found footage film created in 1980. Other recent attempts have been the REC movie series and the critically acclaimed Norwegian motion picture The Troll Hunter. For some reason, it seems as if the genre lends itself best to horror and suspense films, but there is no reason why it wouldn't be equally effective (if not more so) in other genres as well.
Since it's so cheap compared to more traditional productions, found footage mockumentaries will continue to be made and will likely grow in number. I just hope they are done well, otherwise they will be just as painful and unwatchable as some cheap student films or bad home movies.