Not entirely true. It's not circulating freely in most of the countries. The governments are imposing laws and policies to regulate crypto currencies. Regulation = No more free movement of currencies like we used to have at the very beginning.
It is possible, but I doubt this is ever going to happen. Even if it does happen, people will start doing P2P transactions. I heard there are some countries where financial institutions are not allowed to be involved with any kind of transaction related to crypto currencies, but their people still use it through p2p platforms.