So here is a question. According to this article: http://fortune.com/2017/11/25/lost-bitcoins/
approximately 4 million bitcoins have been lost. With North Korea mining bitcoins like crazy, it is possible that even more would be lost if they were attacked by the USA and people there lost access to their private keys.

It would be interesting to calculate the actual real number of Bitcoins left in circulation. What would the new potential price of bitcoin be?