Personally, I see the rise of cryptocurrencies as the beginning of a capital singularity, whereby vast flows of capital begin to outpace and outmaneuver any other collective human organizational mechanism of restraint, eventually and increasingly beyond even the perception of such structures.
I recommend all cryptoholders of a few years consider their long game regarding which coins will be declared, and which will remain in the shadows.
Cryptocurrencies allow for freedom beyond the practical control of agencies such as the IRS, IF you are willing to put in the time and effort. Think very carefully before voluntarily clipping your own wings.
Premeditated tax-negligence is fraud according to the IRS, but the thinking remains.
How many convictions will it take? Depends on how much is on the line.