Surveillance is becoming more and more important in the recent years. In many cities, cameras have been set to look after parks, streets, roads, facilities and so on, however this fact is rising concerns about privacy. In this work, an alternative surveillance method which gather at once security and privacy has been propose and tested. Based on fiber optic specklegram technology; a system consisting of a fiber optic, a coherent light source and a photodetector has been placed under a carpet for detecting people walking over it and its accuracy, regarding measuring the steps, have been measured. Results suggest that using low exposed geometries along the carpet and basic processing methods, it is possible to detect with more than 95% of accuracy the number of steps done by the person walking over the carpet.