Bitcoin is legal by some countries but some countries still not accepting the bitcoin.
What you think is Bitcoin become legal in all countries?
it depends on the contribution of cryptocurrency to the countries economy... countries will regulate first and educate their people on the system of cryptocurency how it runs! how to use it... i think before it will be accepted to the countries first requirement is, could it help the country in their monetary funds, second, the availability of technology to use to operate the transaction. third would be the impact of the currency to the ordinary people.