USA IP can no longer access the game?

I've been playing EU Tera for about 1-2 months (even though I live in USA) and everything was good until yesterday. Now I can't access the game without having to change my IP, which is against the rules and wouldn't help with my already 100+ ping. Was there a sudden IP-Block for people from USA? I really want to go back to playing EU Tera with my friends, but seems like it's no longer an option if the IP-Block will continue.