Could have easily escaped the UK 'video nasty' list if the original pre-VRA video cover wasn't so graphic. it featured a very bloody close-up of a drill boring into a man's head with lots of blood. The video cover was featured in video catalogues and received many complaints.
Abel Ferrara claims that half of this movie was shot in 1978 and the other half was shot in 1979. This explains why the actors hair styles and looks in general change quite frequently during the movie.