Someday! Funny that you should say this but David Cameron wants us to never be left alone by the state and anti terror laws are regularly used against people who are not terrorists. The police are being militarised and the human rights act is being removed from law here in the UK. Someday looks like tomorrow to me.
Probably not terrorist but maybe extremist? If you haven't heard that's David Cameron and Theresa May's current choice of undefined term for people they want to attack but that haven't broken any terror laws (or any other actually).
Someday having anti-american opinions might equate with being a terrorist.