In this article, we introduce <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I Control My Space</i> (ICMS), a novel, fine-grained, and flexible system that allows space owners to define and enforce access restriction and service policies on mobile devices at their premises. This is achieved by enforcing restrictions on the use of applications and even specific permissions on the mobile device (e.g., camera, microphone, etc.). The system is built around a centralized database, where space owners can securely define their restrictions or even delegate control of their space to another owner. ICMS is designed with abstraction in mind so that it can be customized on existing access technologies and platforms—such as Android-based mobile devices—for various levels of security and privacy. A proof-of-concept prototype of ICMS is developed under the Android operating system, and promising results of its performance and effectiveness are demonstrated.