# Privacy and Security Issues in Online Social Networks
## 5 Recommendations  
OSNs have a number of privacy and security issues, but various privacy challenges can be overcome by using precautionary measures. An attacker exploits security and privacy issues in OSNs due to the negligence of users. The contents shared by OSN users with their friends may go to the wrong hands, either in the same format or in a different context. Similarly, contents that are shared can be merged with other public datasets using reidentification techniques where a profile may be reconstructed that can further disclose personal privacy [45]. The frontline defence against such privacy threats is provided through the privacy settings that are controlled by OSNs. However, the effectiveness of these privacy settings is not sufficient because it is designed in the form of an agreement with its users to collect more information from them rather than protecting their privacy. The following are our recommendations for the protection of user contents and the privacy from unauthorized access. **Privacy settings**: Regrettably, 80% of users neither check their OSNs nor know about the privacy of their profile whether they have been offered default privacy settings or adequate privacy that meets the expected level [46]. Although OSNs offer a particular level of access control to data owners via customized settings so as to hide contents from unauthorized access, the default  
Figure 1: Percentage of users who either do not know or care about their privacy while using OSNs. privacy settings of almost all OSNs have restrained privacy [47]. Different social-network users keep the default security and privacy settings [48; 49]. OSN users are recommended to keep customized privacy settings and take maximum advantage of the privacy-protection techniques provided by their OSNs. Similarly, users are advised to frequently revise their privacy settings because various OSNs change their privacy settings after every update. **Personal Information**: Once contents are shared through any third party, there is no guarantee that these contents would be private anymore. Therefore, users are required to avoid sharing unnecessary private data on OSNs. Even though a user might understand the importance of privacy, the privacy policies provided by the OSNs often create confusion about the privacy of contents that a user shares on them [50]. For example, research found that 94% of users were sharing contents on OSNs that were intended to be private [51]. **Location Information**: A number of mobile apps collect user-location information. This location information can be used by OSNs and may be provided to third parties, primarily for commercial purposes, which leads to privacy leakage. Individuals cannot use such type of location information collected by OSNs, but they often share their locations with their posts. Attackers can misuse this location information by knowing your current place. Therefore, users are recommended to not disclose their location information through OSNs in order to be safe from these potential attackers. **Antivirus and Antispyware**: An OSN is one of the leading means of communication between individuals where content distribution can be easily done [52]. Using the nature of content dissemination through OSNs, malware distribution has grown exponentially [53; 54]. Malware is any type of malicious software used to disrupt user operations, illegally gather sensitive information, gain unauthorized access to private data, or inconvenience users through unwanted advertising pop-ups [55; 56]. OSN users are recommended to install antivirus and antispyware software on their computers/mobile phones to counter these types of malware and spyware. **Third-Party Applications**: Third-party apps give rise to a number of privacy and security issues because their code is hosted outside the OSN and user controls. This inherently prevents the OSN and users from controlling and monitoring the app's activities, and to take proactive measures to stop malicious penetration.