I think bitcoin is a world currency not a private currency and because he does not hold by the government and does not have tax.. and i am agreed for this currency. so all people are wrong tell us bitcoin is a private currency.
Bitcoin can not be considered a private currency, since it does not belong to any private person. He does not belong to anyone, no one has a patent for his invention.
However, bitcoin can be called a private currency in the sense that it is more used and, apparently, will continue to be used by private individuals, rather than state structures and even by not very active business structures due to its high price volatility.