the film was called in by the independent broadcasting authority (iba), the regulator of british independent television at the time, for a formal screening before the full board, after iba staff members who had been shown a preview copy flagged up concerns about the title and the extensive use of actual names in the programme. this was a highly unusual step, which had not been taken for many years. for example, similar action had not been taken before the showing of thames television's controversial "death on the rock" in 1988, nor for granada television's drama-documentary "who bombed birmingham?" about the birmingham six earlier in the year.