The grand-daddy of the current crop of electronic currencies is, of course, Bitcoin. In recent months, its value has appreciated exponentially until it reached more than 5,000 dollars. But it's just the most famous so-called "cryptocurrency" and now the technology is "in the wild," anyone with the necessary, apparently not very advanced, IT skills can make one. China says "enough is enough" and is taking steps to more or less outlaw cryptocurrencies or, at least, to make their use difficult. China has explained its reasoning - and it makes a huge amount of sense. The questions are whether the horse has already bolted, can access to cryptocurrencies outside China be banned and just how much use is it really for money laundering, a main plank of the Chinese objection.