Nine years since the birth of Bitcoin, central banks around the world are increasingly recognizing the potential upsides and downsides of digital currencies.
what to do, if anything, about the growth of the private cryptocurrencies that are grabbing more and more attention for a host of reasons: security concerns after a $500 million exchange hack in Japan, volatile price moves and in the case of Bitcoin, at least  their introduction on regulated derivatives exchanges. The second question is whether to issue official versions.So these types of reasons some countries do not support Bitcoin.