This film was effectively "banned" (not rated by MPAA at all) in the U.S. following protest by Women Against Pornography.
Troma had the film cut to gain an "R" rating, then shipped the unrated print to theaters telling them it was the R rated version. Eventually it was discovered when a woman complained the film upset her child. Eventually the MPAA sued Troma for improper use of the "R" logo.
Director Joel M. Reed didn't want to make the movie at the beginning. He had another script he wanted to do, about a rock star haunted by a teenage girl groupie, and he was trying to get money to finance that picture.
Originally titled "The Incredible Torture Show". Troma re-named it "Blood Sucking Freaks" for its 1980s re-release.