Based on discussions of hybrid space as well as the concepts of the database and archive art, the paper analyzes Hasan Elahi’s project “Tracking Transience” (2003-) and relates it to Sophie Calle’s performance “Detective” (1980) while discussing how we can understand the mobile phone as a device that is capable of creating a ‘database shadow’ of the mobile phone owner. Elahi created “Tracking Transience” after he was held back by the FBI in 2003 on suspicion of being a possible terrorist; by consulting the website trackingtransience.net everyone now has access to the data generated by Elahi and his mobile phone, which meticulously tracks his life. However, even though Elahi’s life seems to be thoroughly and intimately documented with pictures of e.g. every eaten meal and every visited restroom, we are clearly not getting the full picture. Consequently, despite having been granted access to an enormous amount of data, we are left with a feeling of following a shadow or maybe a mirage. This paper explores how the mobile phone affords this playing hide-and-seek, and the way that it provides shelter from the inspecting eye.