## 5 Discussion
### Domains, Attributes, and Variables
Photographs' power of representation is one of the major findings of Table 1, as all five attributes of SI can be communicated. Disclosed SA through photographs can trigger privacy implications which should be investigated, focusing on the social aspects of SSE. Gender discloses information about the user's Face. It can also be revealed through one's relationship status and sexual identity or orientation [13; 35; 48; 65; 69; 73; 74; 75]. For example, Tinder, a location-based real-time dating application, uses mobile media services for communicative purposes among people who are interested in meeting new potential partners [65]. However, combining gender and location can trigger neighborhood attacks. Neighborhood attacks signify the access of third parties to a user's friend account, and the susceptibility of the user to targeting, surveillance, or re-identification [14]. Users' Faces can be revealed through age groups or their exact birthdate. Except for direct unveiling, users reveal information about their age covertly, via school information (combined age and place of origin) [48; 69; 75]. Another common practice is to share their year of graduation [74]. Face, Frame, and Stage can be assumed by having access to users' demographics. These include addresses or permanent places of residence, hometowns [3; 45; 69; 74; 75], high schools [45], zip codes [69; 75], countries [69; 75] and regions [72; 76]. Face, Frame, and Stage can be extracted by users' contact information, through Email addresses [10; 48; 69; 74; 75] or phone numbers [3; 19; 45; 48; 69; 75]. The email address is more prone to disclose users' SA than a phone number, as it can contain real names, age, birthdate, workplace, or address if a professional email is used. Phone numbers may disclose geographical information through regional codes. Education, affiliations, or a user's job are other important attributes for when users want to represent themselves on SM. These attributes represent the second most important \begin{table}
\begin{tabular}{c c} \hline \hline
**SI Domains** & **SA on SM** \\ \hline Face & 1–6, 8–18 \\ Frame & 3, 7–11, 13–14, 17–18 \\ Time & 3, 10–11, 12, 18 \\ Stage & 3, 7–14, 18 \\ Activity or Performance & 2–3, 10–18 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Social Identity Domains and Social Attributes on Social Media. finding in our paper, as they can disclose all five domains of SI. Institutional affiliations carry a plethora of implied conclusions about the user [18; 35; 48; 60; 74]. Status and role appear as \"a collection of rights and duties\" [19] (p. 164). According to this point of view, \"husband\", \"professor\", \"employee\", or \"friend\" are statuses, which carry certain roles, social norms, or behaviors [19; 26]. A common practice among academics is to use SM applications to post about their research to engage researchers of similar subjects [18]. Users disclose Face, Stage, and Activity in one post. Educational background and occupation are susceptible to making mutual assumptions about the existing or future groups of interests of users' CVs, and they can be linked to marking social class or drawing inferences about their tastes [77]. Face, Time, Stage, and Activity or Performance can be drawn from disclosing personal websites. Disclosing personal websites can be linked to users' common practice of linking different SM platforms. Linking accounts provides advantages, such as better representation or easier access to platforms, yet it poses additional privacy implications due to probable identification by malicious attackers. Friends' network and users' audiences are important for representing one's persona, as Face, Frame, Stage, and Activity or Performance might be disclosed. SM are social constructions and users' identities are powerful tools for reaching audiences and conducting social performances [39]. Friends' networks may carry geographical connotations as far as our close friends or the majority of our acquaintances are concerned.