Shadow Information Technology (IT) occurs when users develop systems outside of the central information technology department. It provides both benefits and risks. Users procuring shadow IT often do not consider integration with existing enterprise architecture, privacy and security protection, maintenance cost, and legal ramifications. Problems with shadow IT must often be resolved by central IT. It is, thus, important for central IT to determine when users will consider shadow IT, and how shadow IT can be managed. This research analyzes paired interviews with CIOs and senior users to identify factors causing shadow IT. The paper finds that the form the shadow IT/central IT duality takes is based on: (a) perceptions of legitimacy of the Shadow IT by the organization and central IT; and (b) the ability of user departments to procure IT independently.