Because of its capacity to alter the perception of the surrounding environment, mixed reality technology (MR) has potential for in-the-wild management of anxiety—both chronic (e.g., anxiety disorders) and acute (e.g., situation-induced anxiety). Recently, several components of Cognitive Behavioural Therapy leverage these technologies as part of ongoing cognitive restructuring or as part of relaxation or exposure experiences. However, while most of these researchers focus on the promising benefits of these technologies, a deeper discussion on the potential harm through the misuse of these techniques is still missing. To ignite a conversation about the two sides of the same coin of MR for mental health, we present several scenarios where mixed reality approaches might be used to deceive users rather to support them.