Introduction Horkheimer (2002, 188-243) distinguishes between traditional and critical theory. Traditional theory is considered as a form of academic thinking based on instrumental reason, where the reason becomes an instrument for the advancement of external and alienated interest. Instrumental reason is oriented on utility and productivity. In contrast, critical theory may be described as a form of academic, normative, and partial reflection based on critical reason. Critical reason operates with Marxian categories such as class, exploitation, and oppression. Critical theory struggles for the transformation of society and the realization of human potentialities. Based on these ideas, I distinguish between traditional and critical research of privacy and surveillance on social media. The subsequent sections are structured according to this distinction. In the second section, existing empirical research of privacy on web 2.0 is analysed. A discussion of some of the most cited studies should give a representative overview of typical empirical research approaches that assess privacy on social networking sites. I will show that there is a predominance of traditional and uncritical research in the context of privacy on web 2.0. This research does not reflect structural power asymmetries in capitalism. Some critical theoretical studies about surveillance on digital and new media are thus examined in the third section. The studies and any important findings are briefly summarized in order to provide an overview of the existing research. The fourth and final section summarizes and concludes the results, and argues for the need for a critical empirical study of privacy and surveillance on social media.