Introduction

Several conceptualisations of privacy exist.

The first considers privacy to be "the right to be let alone" (Warren and Brandeis, 1890). Thus, privacy is the right to social retreat.

The second considers privacy to be the right "of individuals, groups and institutions to determine for themselves when, how and to what extend information about them is communicated to others." (Westin, 1967). In other words, privacy is the right to informational self-determination.

The third (Nissenbaum, 1997)

In this theory, privacy equals contextual integrity.

The forth considers that "privacy is the freedom from unreasonable constraints on the construction of one’s identity" (Agre and Rottenberg, 2001). This views privacy as a freedom from constraints.

The basic concepts related to privacy include: data, actors, purpose, consent, obligations and retention period.