Some media shows that bitcoin can be the next weapon to control the world economy. i think it is true and it will be seen soon.
How many things that we can say for sure is that we will see that when the time will come, and not sooner than this point. If bitcoin will be unavoidable replacement for the existing currencies, we will see that.
Actually it was true that someday, cryptocurrency might take over fiat due to the demand in the market and that is the reason why some of the governments are afraid about the growth of cryptocurrency.