Specifically answer of this topic is very tuff. Because Some country announced Bitcoin as legal currency and Some country consider Bitcoin as a illegal currency. Although some years ago Bitcoin was illegal currency for most of the countries. But gradually it being legal i think.
Because gradually world wide people and government understanding of Bitcoins importance. It’s usability increasing rapidly. So many country declared bitcoin as legal currency and also many country’s government are thinking how to legalized it. Huge Bank and other big big investor including and investing on bitcoin. So i think gradually Bitcoin will be legal.
From the inception of Bitcoin, there have been lot's of argument over the legality of Bitcoin and the face behind the innovation. Till date, that question is still very much unanswered but bitcoin has gained more popularity than most of the nations still doubting and being sceptical about the existence.
However, government and nations are still observing it while some are already implementing it and integrating Bitcoin into their system as an asset, investment and lots more that could be of benefit to their nation as a whole.
So therefore, be it legal or illegal, Bitcoin has come to stay and has made way for itself till time. The adoption rate is fast increasing with speed and in less than no time, the world would be speaking the Bitcoin tone.