Social Networking Websites are not only the most widely used tools to facilitate communication in today's digital age, but they are also one of the biggest sources of Big Data. There are of course many benefits of data applications, for both ordinary users and professionals alike, but also there are many risks, that users of Social Networking Sites can face. As users' interest in using Social Networking Websites grows, so does their concern about the risks they pose. The purpose of this thesis is to investigate the risks posed by the use of Social Networking Websites to adult users in Greece and examine the behaviors of users that may lead to risk exposure, (behaviors such as Risk Taking, Privacy Behavior, Trust in SNS companies, Privacy Concern, Perceived Control of Information, Information Identity Disclosure will be examined).It will also examine the correlation of user behaviors and exposure to risk and socio-demographic data of users. The results of the present study show that exposure to Risk in SNS is related to gender and also “Privacy Behavior” and “Information Identity Disclosure” are related to Age and Educational Level