The users of social media sites are exposed to different attacks from criminals, who try to steal their personal information, their privacy and cookies from sites. These attacks can also be used against e-government applications using personal credentials taken from social media. In this paper, we explain how the privacy of users is threatened form criminals in social media networks. We demonstrate the causes of privacy leaks along with real online social networks. Furthermore, we illustrate the privacy considerations such as Anonymity, un-observability, un-linkebility and intractability. Finally, we study the classification of social media attacks which are classified to three categories that are Identity Theft/personal information attacks, Spam attacks and Malware attacks. Also, we explain the common attacks for each category. Moreover, we clarify the effective countermeasures against each attack that goal is to protect personal information of users. For instance, Identity Separation approach is used against De-Anonymization attack while Spam Filtering/Blocking Software approach is used against Simple Spam attack.
Cyber Security Threats;, Social Media;, Online Social Networks;, E-Government Security.