Most governments already have wording in the tax code to report earnings from other sources like cryptocurrencies.  You can "choose" to not report and use strategies to hide income but use at your own caution as the governments always play catch up and could find out years later and audit you.  Look at all the offshore accounts in tax havens that WIKI leaks exposed putting hundreds of people in the spotlight.

I like sleeping at night, so if I make it big in crypto I'd just report my earnings and keep it legit