It’s been four years since the launch of bitcoin and not a day goes by that crypto-currency is not mentioned in the tech press. The buzz has gone so mainstream that I regularly field questions about bitcoin from the most non-technical people in my life, many of whom heard about it on TV or read about it in mass media. Given this, it’s hard to imagine that just two years ago Eric Schmidt, who was at the time the CEO of Google (he is currently the Executive Chairman), was barely aware of…