As if Zhou Xiaochuan didn’t have enough to worry about, the central bank governor now has a bitcoin problem on his hands. In a new report, Goldman Sachs says the yuan is now used in 80 per cent of transactions into and out of the cyber currency, topping the US dollar, yen and euro. Given that the Communist Party’s highest priority is stability, and the rampant use of bitcoin represents nothing if not the opposite, it’s probably only a matter of time until Beijing tries to crack down. It wouldn’t be the first time. In December 2013 – at a...