Basically the application of tax on bitcoin, I think it's certainly depends on each country, for the countries that has already legalize bitcoin.. of course maybe bitcoin tax is really applied and can be paid directly with bitcoin. But for the countries that hasn't really legalize bitcoin, of course we do not must to pay taxes with bitcoin directly that we earn. But as good citizens, of course we still can try to pay taxes as can.. we can pay taxes from the money earned from bitcoin incomes.