## 2 Literature Review  
### Privacy Paradox  
In 2006, [PERSON] first realized the \"privacy paradox\" phenomenon in behaviors of social media users [16], namely, the discrepancy between users wary of risks of privacy leaks and disclosing personal information lightly when using social media. Afterwards, a number of academics investigated the causes of this phenomenon from multiple angles. Generally, angles of explanation can be divided into these two-: the opinion perspective and behavioral perspective. Researchers from the opinion perspective consider privacy paradox to be caused by a rationality limitation in the users, namely, the users are constrained by influences from internal and external environmental factors, engendering cognitive biases on estimating the risks of privacy disclosure. Several user cognitive biases are exhibited, for example: (1) optimism bias, which is when people's perception of the risk of privacy leakage is based on descriptions of non-personal experiences. Therefore, when making decisions about privacy violation of disclosure risk assessment, people often have an optimistic illusion that they are luckier than others. This bias is present all over the world. As examples, a study in South Korea found that the experience of privacy infringement affects people's level of optimism. Users who have no experience of privacy infringement are more optimistic and more inclined to adopt privacy protection behaviors. Research in Singapore concluded that an individual's prior experience and cognition control significantly affect the degree of his/her optimism bias [17; 18]; (2) self-confidence bias, which refers to the degree to which an individual's prior experience and cognition control will significantly impact their optimism bias; this bias is reflected in the user's high confidence in their ability to cope with privacy disclosure or risk of being violated, that is inconsistent with reality. Research data revealed that among those users who have a high assessment of their own privacy protection techniques, less than a quarter of those really know how to prevent privacy risks through technical means [19]; (3) hyperbolic discounting, which refers to the user's perception of long-term and short-term benefits and the influence of time factors in the measurement; that is, the user's perception of benefits will weaken with the lapse of time. Therefore, long-term benefits will be underestimated since they are in the future [20]. The lines of research from the behavior perspective mostly make use of the privacy calculation theory as theoretical support. Based on the \"rational person\" hypothesis, after balancing risks and benefits as a whole, participants in socio-economic activities would attempt to achieve the greatest gains with the least cost. During the process of privacy calculation, there are diverse benefits that can be sensed, such as obtaining economic benefits or social benefits, displaying individuality or attaining convenience. Benefits are also built up based on demands for social capital, entertainment, social relations and identity construction [3; 20; 21; 22]. Studies have shown that in making decisions on disclosing privacy information, users would evaluate the respective weights of privacy risks and sensed benefits. When benefits are sensed to be greater than risks, users would choose to disclose privacy information [23]. Nonetheless, the works above mainly focus on opinion and behavior inclinations, ignoring the influence from users' emotional cognition on the privacy paradox. According to the cognitive dissonance theory, psychological pressures will be produced when an individual experiences cognitive dissonance. To lessen the pressures of this uncomfortable psychological state, the individual will look for outlets to reduce the dissonance to arrive at the balanced state of cognitive harmony.