Bitcoin is decentralized in nature. There is no regulatory authority to regulate Bitcoin so far. No government can control over it's trade, transaction, use. Only govt. can impose rules on use and trade of Bitcoin. That's why in many countries, it is still illegal to use but they can't destroy Bitcoin. It is still dominator of virtual currencies. There are many obstacles of using Bitcoin in many parts of the world but popularity, demand and price is on the rise if you compare in the last 5 years.