The rapid rise of decentralized online social networks (DOSNs) introduces a transformative shift in digital communication, moving away from centralized systems and leveraging blockchain technology to ensure user autonomy, data transparency, and resistance to censorship. While these platforms promise significant advantages, such as enhanced privacy, reduced operational costs, and increased interoperability, they also present critical legal and ethical challenges. This study explores these challenges through a multidisciplinary approach, integrating legal analysis, case studies, and theoretical frameworks. Key issues include the tension between immutability and content moderation, the complexities of jurisdiction, and the implications of blockchain splits for accountability and governance. The analysis highlights the need for hybrid solutions that combine decentralized architecture with external oversight, including stricter regulation of hard forks and designated regulatory responsibilities. The findings provide a roadmap for balancing innovation with user protection, aiming to foster sustainable, ethical development of DOSNs while addressing their inherent risks.