Micro-targeting campaigns on online social networks are an emerging class of social engineering attacks that prime individuals via personalized content for malicious purposes. Detecting micro-targeting campaigns is challenging due to their clandestine nature and the lack of visibility around users’ private communications. Our work aims to devise theories, methods, and tools to detect suspected micro-targeting campaigns. To this end, we propose to design and generate a network of decoy personas with characteristics similar to those of targeted groups in order to trap, engage, and identify micro-targeting campaigns. In this paper, we discuss our motivation to conduct this interdisciplinary research effort and introduce our focal research questions and preliminary design for a network of decoy personas.