I don't think that any government can regulate bitcoin alone, because they can't control Internet.
Only some kind of regulation on the world level is possible, but I doubt it will happen soon.
Governments can control income from bitcoin and crypto currencies when you decide to exchange your btc funds to the fiat money.
In the most countries, I believe, you will have ti report it and pay tax.
Just a regulation when converting your Bitcoin/crypto into fiat currencies. Which already exists. Bitcoin can't be directly regulated, but they can make it extremely difficult to convert it into other assets such as property, and other things.
Some countries consider Bitcoin capital gain, and therefore you would need to report it to the tax man regardless if you've converted it to fiat or not.