I ran across this video a while ago on what can happen to you if you don't pay your taxes. At some point during your Bitcoin career, the cryptocoin will be converted to fiat and that's how they will catch you.
https://www.youtube.com/watch?v=hf2fNEUPjQwIn the end, government will find out about our assets. Its better to paying our tax because we get profits from cryptomarket. Not matter we hide our assets, I am believe government will find out because in digital world anything can be tracked