Income tax has become a dilema especially in cryptocurrencies however speculating about how government will take how much percentage of tax due to how much coins we have or trade doesn't sounds really fair since decentralized and annonymity were included and theres no way to deduce it someone really owns it or even trade it at the first time. I don't live in US but if government really apply cryptocurrency taxes in anywhere then they have to make sure they can calculate and measure how much someone really worth first.