Through online activities, we produce a large amount of personal data traces every day. Many people acknowledge the significance of protecting personal data online but they might not act accordingly. This thesis project seeks to make these often hidden traces visible and thus understandable through a data physicalisation. This is to increase awareness and knowledge as well as spark reflection on how and if certain data should be protected. Six design activities with a focus on the active involvement of participants were conducted to create the concept of “OODOOLL”, a reversed voodoo doll that has the purpose of protecting users from any potential harm in relation to online activity and sparking reflection around the topic of data privacy. While some of the potentials of a data physicalisation, such as initiating conversations or increased levels of self-reflection, could be realised, there were several limitations to the concept, i.e. technical limitations or breaking down the complexity of aggregated data use. Especially in terms of the increased use of digital devices and the rise of emerging technologies, it is important for general users but also for interaction designers to be aware and have an understanding of data collection, data use and data protection.