It is a chill February day in London in 2018 and a small demonstration is taking place outside a cinema just off Piccadilly Circus. Wrapped-up warm, the quiet protestors are holding up posters that say “Silenced” in capital letters. Most Londoners trying to get to their bus stops or across to the bars of Soho barely notice them. A passing couple clock that the group is mainly middle-aged and elderly. One says to the other, “Some kind of UKIP protest I guess.” But it is not. The assembled dozens came here to watch a film called Voices of the Silenced. But as their placards point out, Voices of the Silenced has itself been silenced. The organizers booked the cinema three months earlier, and say they had complied with all the cinema’s rules for private screenings, including sending them the film in advance. But a day before the screening Pink News—an online remnant of Britain’s gay press—found out about the screening and called for its immediate cancellation. The call was successful. The Vue cinema swerved around …