The Paris police faced considerable problems in trying to identify migrant workers who, during the Algerian War, provided a support base for the Front de libération nationale. In order to overcome the failings of manual card-index systems (fichiers) the Préfecture of Police experimented in 1959-62 with IBM punch-card machines. The origin of these powerful identification techniques can be traced back to the inter-war statistical services headed by René Carmille. Although such methods were banned after the Liberation because of their repressive potential, they were discretely revived to track Algerians. Although the experiment proved successful, the proliferation of numerous decentralized fichiers continued to make the process of identifying wanted Algerians slow and cumbersome and this enabled FLN clandestine networks to survive intact to the end of the Algerian War. However, while rapidly superceded by true computers, the punch-card experiment was a precursor of contemporary, high-speed "Panoptican" systems and the computer driven" "révolution identitaire".