THE

good news is that a technology company has invented a device which jams mobile phones being used loudly on public transport to play music or video games. The bad news is that there are no plans to manufacture it commercially. So I shall just have to persevere with my own project — trying to invent something that delivers a nasty electric shock to anyone watching Game Of Thrones or listening to hip-hop on the Underground. Until then, a discreet cattle prod might do the trick . . .