The idea has been used here successfully before, by a convenience store experiencing the same sort of loutish behaviour. However, "London subways" are not what is under consideration in the Guardian article you linked to. Subways in London are tunnels from one side of a road to the other, to enable pedestrians to cross the street safely. :) The article was about the "Tube", the London Underground railway system.
I've read that the playing of Barry Manilow music among some of Australia's young people has been effective in driving them away from bad behavior . They leave the scene when his songs are played .