(It can be from a video game or something else. Where you seen fans really get pissed over something)
For me the most pissed off fanbase I seen was from a video game called Socom 4. The developers zipper received nothing but hatred after that game was released. Alot of people was pissed because they felt like the game was for the more casual gamer. Everything they liked about the original socom games wasn't in socom 4. In socom 4 you couldn't be as tactical, pistols was removed, the game was more linear, and alot of the features from the previous socom games was gone.
People raged on the forums and made hate vids towards zipper. Calling zipper abunch of sell-outs and corporate assholes. They felt like socom 4 went in the direction for the call of duty fanbase. After socom 4 was released zipper lost alot of respect from there fanbase.