Bayern Munich has got a well-organized ultra scene. The most important groups are the Schickeria München, the Inferno Bavaria, the Red Fanatic München and the alarMstufe rot.
Some Schickeria members are known for their propensity for violence. But according to some sources they aren't more than 100.
The change of Manuel Neuer in 2011 from Schalke to Munich made some disuputes between the ultras and the board made of Bayern. The ultras were against the change and organized lots of banners etc. against him in his first matches for Bayern.
Politically the ultras of FC Bayern are on the left side, as they often demonstrated with banners. In the right scene FC Bayern is referred to as a "Jewish Club" because of his past.
The ultras of Bayern Munich have got a friendship with the Ultras Bochum (VfL Bochum), with the Horda Azzuro Jena (FC Carl Zeiss Jena), with the Ultras St. Pauli (FC St. Pauli) and with two Italian groups, the Brigate Rossoblu Civitanova (Civitanovese Calcio) the Ultras Samb (U.S. Sambenedettese 1923) and with the French Ultramarines 1987 (Girondins de Bordeaux)
Bayern's main local rival is TSV 1860 München, who's now in the second division. The Munich derby is still a much anticipated event, getting a lot of attention from supporters of both clubs. Despite the rivalry, Bayern has repeatedly supported 1860 in times of financial disarray.
Since 1920s, 1. FC Nuremberg has been Bayern's main rival in Bavaria. The matches between the two clubs are "always special" and there is a "heated atmosphere" said Bayern's captain Phillip Lahm. The duel between Bayern and Nuremberg is often reffered to as the Bavarian Derby.
Since 1970s, Bayern's main rivals have been the clubs who put the strongest fight against its national dominance. Recently Borussia Dortmund and Schalke have been the main challengers in the Bundesliga.
Bayern has also got some European rivals, as Real Madrid or A.C. Milan.