More control is good, especially in terms of exchanges. There were a lot of fishy "hacks" (wink wink nudge nudge) and "bankruptcies" in the past that I can't believe that there still are unlicensed exchanges out there. Instead of figuring out how to tax cryptocurrencies, I think the most important and urgent task of any government is to come up with regulations for exchanges, and they have to shut down any exchange that doesn't comply.