In the past couple of hours there were news of the president of Venezuela claiming to be creating a new cryptocurrency called "the petro" which would be a private blockchain that is backed by their oil reserves:
http://www.zerohedge.com/news/2017-12-03/petro-venezuelas-maduro-announce-launch-first-government-backed-cryptocurrencyThis will be a good practical experiment in real life to see how private blockchains work. Of course I don't have much hope in they managing this properly given their track record, but it's worth paying attention to to see how it goes. This can only be positive for bitcoin in any case, the amount of headlines this is hitting is amazing, and they all mention bitcoin.