The challenge in intelligent environments is to overcome the dual forms of the Invisibility Problem, specifically when it comes to managing security and privacy in such environments. We present a user study (N = 17) that informs the design of the personalisation that needs to be done to enable users to effectively negotiate and control an intelligent environment, in particular the MyPlace system. This user study finds that trust is a critical aspect of intelligent environment design. Effective feedback to the user and the management of information flow across physical, social, and temporal borders is essential to maintain user trust. Users are able to understand the invisibility problem, and are willing to share personal information to receive a tangible benefit from personalisation of intelligent services.