The implementation in France of the SNIIRAM (National System of Interregime Information of Health insurance), reopens the debate on the opening by the State of the public data to the private sector and the risks it implies. In the field of health data it puts in balance the search for rationality which it would allow (in the fields of research, prevention, marketing, medical security) , and the risks of the mercantile exploitation of the sensitive data and the private life.