The storage of personal information is durable and the ability to aggregate, analyse and draw sensitive inferences from individuals’ data is advancing. Both companies and individuals can benefit from sharing information and the application of sophisticated analytics. However, the potential negative effects are great (e.g. discrimination, manipulation). The erosion of privacy can threaten one’s autonomy as a citizen. Sharing more personal data does not always lead to more progress, efficiency or equality.

The degree to which people value and perceive the need for privacy depends on the context and context-dependence is amplified by uncertainty. Privacy preferences and behaviours are subject to influence because they are context dependent (1) and those with an interest in information divulgence are able to manipulate context to their advantage (2). People are often unaware of the consequences and their feelings of privacy.

Individuals manage the boundaries between their private and public spheres via separateness (1), reserve (2), anonymity (3), protecting personal information (4), deception (5) and dissimulation (6). These boundaries are established because of the need for intimacy and the desire for protection from social influence and control. People often experience uncertainty about whether and to what degree they should be concerned about privacy.

The uncertainty of the potential consequences of privacy behaviour is exuberated because the costs are intangible (1) and privacy involves trade-offs (2). This can be overcome by making both factors explicit.

People are also unsure about their own privacy preferences. There is a discrepancy between privacy behaviours and privacy attitudes called the privacy paradox (i.e. people claim to care a lot about privacy but do not act upon it). It appears as if people value privacy more when they have it than when they don’t. The consistency of preferences for privacy is also complicated by desire to be public, share and disclose.

The social penetration theory states that progressively increasing levels of self-disclosure are an essential feature of the natural and desirable evolution of interpersonal relationships from superficial to intimate.

Individuals often search the environment for cues to provide guidance when people are uncertain about their privacy preferences. The privacy preference of individuals depends on the context. The rules people follow for managing privacy vary by situation (1), are learned over time (2), are based on cultural criteria (3), are based on motivational criteria (4) and are based on situational criteria (5).

The theory of context integrity states that social expectations affect one’s beliefs regarding what is private and what is public. These expectations vary with specific contexts. Privacy concerns are influenced by others’ behaviours and are a function of past experiences (e.g. a new surveillance camera is likely to activate privacy concerns).

Some entities have an interest in and have developed expertise in exploiting behavioural and psychological processes to promote disclosure. The malleability of privacy preferences refers to the fact that various factors can be used to activate or suppress privacy concerns, which, in turn, affects behaviour. Information disclosure is often affected by default settings on websites. Malicious interface design refers to frustrating or confusing users into disclosing personal information. Companies also often do not use overly personalized advertisements to not ring the alarm bells.

The existence of a privacy policy also leads people to believe that their privacy is guaranteed. Control – providing users with the means of accessing their personal information – is an important aspect for people and can reduce privacy concern.

Monitoring can induce people to engage in prosocial behaviour or adhere to the social norms. Prosocial norms can be heightened by monitoring cues