While fan studies, as part of media audience research, has traditionally positioned the fan as one who engages with ideas related to a topic they are exceptionally interested in and enjoy, little research has been done for those who engage just as obsessively with media they claim to oppose, but are still very interested in. They are very similar, but not the same as haters.
From laboriously constructed flash animations/comics/images to extensive websites that extend beyond the minimum need of the work in question, Anti-fans spend a great deal of time, effort and considerable resources defiling, rallying against or creating specific parodies to many different media objects in books, small films, reviews, blogs, and so forth.
Anti-fans will distinguish themselves from other anti-fandoms by specifying the fandom they are opposed to within their name. E.g. Anti-Twilight fans.
It is common for large Anti-fandoms to gather in groups, usually on forums and sites, to share their mutual aversion. These are coined Anti-fan clubs, and some are substantial enough to become Anti-fan sites.
A sports fan dedicated to cheering against a specific team. The concept is derived off of the sports-fan subculture and rivalries that exist amongst them. An "Anti-Fan" is said to cheer for whomever the opponent of their team is playing. This happens often in the set college sports as most colleges have defined or traditional rivals of whom they will never cheer for. This concept was built upon in a set of ESPN commercials tagged "Never Graduate" and "Long Live Rivalry" where graduates of popular colleges interact with graduates of rival schools in humorous agitating ways.
-  - An Analysis of Twilight Anti-Fans
-  - A prominent Twilight Community, referenced in "Books".
-  - A prominent Maximum Ride community, referenced in "Books".
-  - Twilight Fails, an Anti-Fan Site of the Twilight Saga