Perhaps there is little wonder then, why they would back an anti-fracking propaganda film staged in a small Pennsylvania town like Dimock.

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Riefenstahl was a German film-maker who became notorious for her Nazi propaganda films.

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During World War II, Harryhausen joined Frank Capra's film unit, which made the "Why We Fight" propaganda series.

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It goes on to pay tribute to news reels and propaganda films and expressionist shorts and most particularly the work of John Grierson who did this observational documentary film making.

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