In this article we study the evolvement of empowering and dis-empowering aspects of a local memory website, initiated by the Amsterdam Museum and currently active for more than a decade. The results partly fill a gap in the available literature about this field, because the relation between collective empowerment and online behaviour in these communities has been underexposed. Departing from a narrative perspective on memories as resources for empowerment, we show how the online dynamics around these memories exhibit collective processes of identity formation, social learning and networking. However, certain patterns in the online dynamics also uncover that, although the online activity is increasing, the diversity in the content and the number of participants are decreasing. Describing the organizational development of the local memory community, we argue that the growth into a self-organizing community is the cause of increasing activity and decreasing participation. This implies that the online community has become a small, empowered group, which at the same time has developed dis-empowering characteristics, i.e. limitations to include ‘other’ locals, neighbourhoods and topics. We illustrate how the current self-organization, unintentionally, fuels the decreasing diversity in content by a natural selection process of a rather homogeneous group of participants. In addition, the conviction of what constitutes a successful online community is discussed for emphasizing individual empowerment and attracting empowered locals instead of vulnerable ones.