This article examines how social robots, or “bots,” have transformed online interactions and information manipulation, particularly on the platform X (formerly Twitter). It retraces their socio-historical evolution—from early chatbots like ELIZA to AI-driven agents capable of realistic human mimicry. Drawing on the Beelzebot research project, the paper proposes a classification of “malicious” bots according to their technical sophistication, intentionality, and interaction strategies. These bots amplify, polarize, and distort public debate through mechanisms such as astroturfing, fake engagement, and echo-chamber exploitation. The integration of generative AI has produced a new generation of adaptive, persuasive “AI bots” blurring human-machine boundaries. The article highlights how these entities shape information flows, foster disinformation, and undermine trust in institutions. It argues for a socio-technical “archaeology” of bots to understand their evolving power in digital public spaces. Finally, it calls for new multidisciplinary tools—technical, educational, and regulatory—to preserve the authenticity of social interaction and democratic deliberation in the AI era.