Released in 1980, but banned in the U.S. up until just a few years ago when it was finally released on DVD. Ruggero Deodato's
Cannibal Holocaust was the original "Blair Witch Project". R.D. was actually arrested, and taken to court, and had to prove he did not kill the actors while making this film. Not for the squeamish, the animal killings are what kept it banned in the U.S. for so long.
When I was 16 I paid $25 for a mail order VHS bootleg of it, and it changed my life. A couple years ago I had the chance to meet the director, Ruggero Deodato, at a convention. I told him my story of how I obtained a copy when I was so young, and the look of surprise on his face, realizing I was 16 when I 1st saw it, was priceless.
They did an illegal theatrical release of it in the U.S. back in the 80's, and I successfully hunted down one of the theatrical posters from that for him to sign.