Contrarily to the official discourses making them commonplace, the detention centres for foreigners can literally be called camps, namely places where groups of undesirable human beings are maintained under control. They can nevertheless not be compared to the deportation or extermination camps characteristic of totalitarian regimes: their way of functioning and their functions are extremely different. In parallel, or even in opposition to their official functions (to limit migration flows and to organize the repatriation of foreigners that have not been allowed to stay), these camps carry out a series of unofficial functions (symbolic, political, police, economical) or power effects which are situated outside rather than inside the camps. The migration flow control mechanism as a whole contributes to confining the foreigner in the image, the place and the role that our societies reserve him: it is no more question of disciplining a mass of foreign workers anymore, but of managing the undesirable effects of the globalization and using the precariousness of illegal immigrants in order to experiment or further install the repressive apparatus, the deregulation of work relation and the functional or numerical ‘flexibilization’ of work. Thus, the real and symbolic functioning of these camps is part of a more global society scheme: security based neo-liberalism. The security control society succeeds to Foucault’s disciplinary society: what the security mechanisms represent for the globalization and the post-fordist production is the same as what discipline represented for national integration and the fordist production. The fear, which constitutes new realities, which justifies and automatically runs the security oriented power function, actually constitutes its diagram.