It's not illegal. That's good news.
Remember, the IRS only taxes Americans. There are 248 nations.
Ya but thats all american citizens even ones not living in america but living abroad too. Even american citizens that are residents of other countries who are not even living in america anymore still have to pay taxes for being an american citizen and being born in america. Its such a burden and penalty to be an american citizen your taxed everywhere even outside of america.