Blockchain technology is a promising, yet not well understood, enabler of large-scale societal and economic change. For instance, blockchain makes it possible for users to securely and profitably share content on social media platforms. In this study, we explore how blockchain enables and constrains social networking practices by means of an in-depth qualitative study of Steem, a major Blockchain Social Network (BSN). From that, we identify three paradoxical effects of BSN: 1) Freedom and Captivity, 2) Abundance and Scarcity, and 3) Peace and War. Via a dialectic synthesis of the three paradoxes, we theorize the effects of blockchain technology on social networking practices. We discuss theoretical implications for research on blockchain, social media, and online communities and define a path for research on BSN. We also discuss theoretical and practical implications by illustrating the paradoxical effects of using BSN and suggesting a ppropriate coping strategies.