Interesting question. But keep in mind they are government which means they have access to almost everything, even great people, hackers, it, computer geniuses etc. That is why I believe they could hire very smart people to help them regulate cryptos, or maybe they are already doing it, they are only waiting to apply it officially, who knows? Never underestimate the government.
I agree on you, the government had probably watching us now and planning how to catch us in our cryptocurrency transactions. This is also the reason that we need to pass a KYC on those reputable exchanges as those government can use our data if they need it. Anyway, if the government will impose a taxes on our crypto earnings then it's better to comply than fight against them. Indeed our government here is neutral on cryptocurrency as we are free to transact cryptocurrency.