Cannibal Holocaust | 1980

This scene was carefully examined by Italian courts to determine whether or not special effects were used.

When Cannibal Holocaust was originally released in Italy, people believed that it was a genuine snuff film, where actors were murdered so that their deaths could be made into a movie. The film was confiscated ten days after its premiere in Milan, and the director Ruggero Deodato was arrested. The actors had signed contracts with him ensuring that they would not appear publicly for one year after the films release, in order to promote the idea that the film was truly the recovered footage of missing documentarians.

I saw that and it was just plan horrible in every sense of the word.