If the government is against the black money the easier solution is to regulate BTC, because if they ban it, people will continue using Bitcoins and government won't have control over it, regulating can make things easier to manage for the government, what doesn't mean it will be better for ordinary people using Bitcoin for honest purposes.
I think if bitcoin is managed by the government will certainly change all rules that have become bitcoin performance system, of course function of bitcoin freedom will be eroded by new regulations that may be applied by government