<p>Police investigations have repeatedly found that offenders from different countries have widely used closed encrypted communications tools to plan and organize serious crimes. The dismantling of such services (e.g. PGP Safe, EncroChat, Sky ECC and ANOM), alongside the decryption of data, has resulted in thousands of arrests and seizures of significant quantities of drugs, weapons and money worldwide. These services are interesting not only from a law enforcement perspective. This exploratory paper addresses the potential of using such data to study organized crime. Specifically, to gain insight into the nature and structure of organized crime by analyzing the communication and communications patterns of those engaged in it. The data comprise information and connections provided by offenders themselves. Therefore, they are unaffected by potential law enforcement biases and/or subjectivity. First, we consider the generation of datasets and the validity of these data. Second, potential analysis methods are discussed. Closed encrypted communications data appear suitable for both qualitative and quantitative research methods. As they contain information about the underlying qualitative processes of organized crime, these data are of particular interest for crime script analysis, providing detailed insights into how offenders operate and the qualities they possess. As the data encompass communications networks, they can also provide insight into criminal cooperation and relationships. Criminal networks and key players can be identified through social network analysis. Although dismantled and decrypted closed encrypted communications services pose challenges in terms of their analysis, they offer a unique opportunity for further exploration and study.</p>