A night at the theatre used to be a civilised alternative to the cinema: nobody guzzling popcorn or talking loudly, phones switched off and tucked away.
But the behaviour of theatregoers has declined so markedly, according to the Society of London Theatre (SOLT), that ushers have begun wearing body cameras to record aggressive incidents.
It follows a punch-up at the National Theatre, where two middle-aged men came to blows during a performance, and another at the Old Vic in which a theatregoer punched someone during the interval in a row over use of a mobile phone.
At the Coliseum, home of English National Opera and a number of musicals, patrons can no longer take water bottles into the auditorium after some people used them to smuggle in gin and became drunk and disorderly.
SOLT and UK Theatre have partnered with Calla, a security company, to introduce body cameras for front-of-house staff. Pilots have taken place at a number of venues.
They are a “pre-emptive measure to ensure that theatre staff feel supported”, SOLT said.
Phillip Brown, the organisation’s head of risk and safety, told The Stage newspaper that theatres have reported “increasing levels of aggression towards staff”.
“When you mix alcohol with the theatre environment, that can exacerbate situations, and we want to try to manage that before it becomes a major problem within our industry,” Mr Brown said.
Some staff have refused to work on certain shows or on Friday or Saturday nights due to the dangers, he said.
A three-month trial at one West End theatre had yielded very positive results, he added. “We have seen in some of the reports from the pilots that people have backed down, calmed down and walked away from situations.
“I think just the fact that people can see themselves behaving in an unpleasant way can sometimes be enough to calm themselves down so they walk away from the situation before it turns into something more significant. So I think body cameras can make a difference.”