The word "mobilization" conveniently identifies the process by which a group goes from being a passive collection of individuals to an active participant in public life. Demobilization is the reverse process. Offensive mobilization is, however, often top-down. In the offensive case, a group pools resources in response to opportunities to realize its interests. Preparatory mobilization is no doubt the most top-down of all. In this variety, the group pools resources in anticipation of future opportunities and threats. Governmental repression is uniquely important because governments specialize in the control of mobilization and collective action: police for crowd control, troops to back them, spies and informers for infiltration, licensing to keep potential actors visible and tame. Contention for power links the mobilization model to the polity model. The word "socialism" itself originally represented the vision of a social order in which producers would control their own fates.