There is growing interest in the role Communities of Practice (CoPs) play in continuing professional development of academics. However, very little research has explored how CoP theory is applied in practice in academic settings. Using the concepts of resonance and micro-mobilisation from social movement theory, we explore academic engagement (and disengagement) in the online aspects of a CoP in a large, multi-campus, multi-disciplinary university business school. Our findings demonstrate that while some found this environment useful and minor patterns of micro-mobilisation emerged, there were challenges in developing resonance using online technologies. Difficulties in finding technologies fit for purpose, concerns about confidentiality online and time jealousy were key issues that need further exploration.