To be overtly defensive of something or someone on the basic premise that said person is willing to overlook logic and reason simply because they are too blinded by their obsession to even consider the possibility of criticism.
Harry: "Hellgate is a great game! Why, all the business decisions Flagship has made and everything they have done are all precise and sound marketing moves! There isn't a single flaw here!"
Bob: "Your fansanity knows no bounds."