German ultras and other active football fans have several reasons to protest in order to achieve a common goal, such as collective punishment, greater commercialization and, therefore, more expensive admissions or merchandise, or the increasing police presence. 'Solidarity', 'cohesion' and 'cooperation' are concepts that relate closely to one another. In order to create cohesion, solidarity is an important part. In particular, solidarity in groups is a difficult matter, since every individual should have an interest in showing solidarity towards rival groups if necessary. Cohesion is a dynamic process that is reflected in the tendency for a group to stick together and remain united in the pursuit of its instrumental objectives and for the satisfaction of member affective needs. The cooperation itself needs, in addition to the solidarity, a reciprocal approach towards each other, always between the priorities of egoism and solidarity.