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 belong to a private person, or a legal entity, or to any particular state or group of states. Nobody owns a document proving that he is the inventor of Bitcoin. Therefore, Bitcoin can be considered an invention of the people. Bitcoin can be considered a private cryptocurrency only in the sense that it will mainly be used by private individuals, and not by government agencies.