This article examines the transformation of the public sphere in the digital era, discussing the symbolic shift from the public square to the “algorithmic fiefdom.” Drawing on authors such as Habermas and Castells, it explores how the initial promise of a democratic digital space has been replaced by private platforms governed by opaque, profit-oriented algorithms. The evolution of social networks is analyzed, from early forums and photoblogs to the dominance of Facebook, Instagram, and TikTok, emphasizing the impact of algorithmic curation on citizenship, subjectivity, and democratic deliberation. The essay addresses phenomena such as filter bubbles, polarization, and digital narcissism, highlighting the risks posed by surveillance capitalism. Finally, it suggests possible paths of resistance, including algorithmic literacy, balanced regulatory frameworks, and decentralized technological architectures, aiming at the reconstruction of a more open, plural, and democratic digital public sphere.