For me I think its legal because it is handled by the Governments in every country whos having a bitcoin but if its not a governments then it is handled by the professionals.
Some countries prohibit the use of bitcoin as a means of payment. However, the government does not prohibit citizens to keep or use them for transactions with legalized countries. The law of bitcoin depends on where we live. In the country where I live, bitcoin is not legalized as a medium of exchange
legalkan , but from the local government there is no prohibition to use or have bitcoin.