In my country crypto currency is still not legal and still no way to audit your total earnings/ taxable income here in bitcoin. So dont bother to pay taxes as long as it was not under your law.
If you tell me what country you are from, I'll be able to point out that you in fact are obliged to pay tax over your crypto holdings/profits, and that without the need of them being explicitly stated as such.
I have seen so many people say the exact same thing, that as long as crypto isn't legal it can't be taxed, but that's wrong to the core. There is always a certain category crypto fits in, don't underestimate your government.
They'll do everything they can in order to make you pay tax over the weirdest possible things, all to squeeze out every possible penny. In other words, don't consider yourself to be exempt from paying tax.