Governments will do almost everything to maintain / increase tax revenue of course. They will clamp down on individual BTC users if they expect a positive return from it. The bigger the user base of an exchange, the more likely its users will be subjected to taxation related surveillance.
Personally I have no sympathy for BTC sellers and I think they deserve some punishment, because selling BTC for fiat money is an act of supreme stupidity...
Why do you want to own fiat, when you already have the best money in the world? Use your BTC for direct purchases of goods and services and you'll have no problems with taxation at all.
ya.ya.yo!