because they are eruptions that happen automatically like the one direction fandom getting into arguments with the wanted fandom, the taylor swift fandom and the union j fandom

Joining a fandom is easy to do. You simply sign up to social media accounts and join groups related to the fandom you like.

There isn't a specific fandom name for The Fault in Our Stars book, but John Green (the author of the well aclaimed novel) has a small following of people called Nerdfighters. He explains about this on tumblr and in his vlogs

An anti-fandom is the group of anti-fans of a television show, movie, book or fictional character.

Cassiopeias