In recent years, the impact of the Italian legislation on the use of personal data (Legislative Decree 196/2003 and successive regulations) on epidemiological research has highlighted the need for reaching a balance between protecting sensitive data and making these data available for public health purposes. Complying with this legislation constitutes a number of challenges in the field of epidemiology, especially with respect to the use for research of health data that have been collected for purposes other than research. Based on the difficulties experienced by the National Center of Epidemiology, Surveillance and Health Promotion of the Italian National Institute of Health, in the present work we aim to promote what we feel is a more rational approach to the concept of "use of sensitive data". In particular, we address the importance of these data for research, the concept of identifiability as defined in current legislation, informed consent, and the lawful use of the data. Given that data networks have been replacing static archives, it is more realistic to strive for the protection of data confidentiality, as opposed to performing irreversible anonymization of data. We also stress the role that research and health institutions should play in clearly communicating to law and policy makers the importance of the data routinely collected by healthcare facilities in performing epidemiological research and surveillance, stressing the invaluable impact of these activities on the health of the population. We also emphasize the importance of strengthening the concept that public health prevention also begins with epidemiological research and surveillance.