"And can anyone explain why dim folk still wander into the seediest clip joints and then profess surprise that the hostess doesn't want to marry them; astonishment that the carafe of Sancerre they shared cost £700. In the absence of explanations, we can but protect them, and so it is that Scotland Yard has gone back to basics. Visitors to a clutch of bars in the racy part of Soho now see outside a yellow board, labelled Police Warning, chained to a lamppost and crafted using the design usually employed to alert the public to murders and muggings. Burly stewarding types can glare - and they do - but they cannot remove it. To do so would be an offence. "It will only cost you £5 to enter one of these premises," it says. "It may cost you £300 to leave." And that's just happy hour. At least there's no binge drinking."