A good understanding of the underlying mechanisms that govern identities on the Web is a key aspect for ensuring the privacy of users but also solving some ethical related problems. This paper proposes SpeculoLab, a platform implementing a strong and well defined experimental protocol for supporting research in the area of multiple identities in the (social) Web. The platform supports an end-to-end control of the experimentation process and, more importantly, allows personalizing and extending every part of the process. SpeculoLab is provided as an open source for the community for further improvements and reinforcement.