Doubts are brought up about the possible utilization on the part of a town councilor of identificatives data of determinate persons who have been given of casualty of the municipal census of inhabitants. The right of access to the information exercised by the town councilors has limitations, but a limitation a priori and with general character, with respect to the particulars in those that can access, does not fit to the regulations about law of access nor is exigible from the prospect of the protection of data. The posterior utilization of the particulars, obtained legitimately by the town councilor, has to found in a determinate, explicit and legitimate purpose. The legitimate access does not fit out another purpose that differs to use the data for any or cannot be considered subsumible in the first purpose and legitimate that founds the treatment. A change of purpose will require to have the consent of the persons concerned or with a habilitation legal.