The demonstration presents the WebdamExchange system, a distributed knowledge base management system with access rights, localization and provenance. This system is based on the exchange of logical statements that describe documents, collections, access rights, keys and localization information and updates of this data. We illustrate how the model can be used in a social-network context to help users keep control on their data on the web. In particular, we show how users within very different schemes of data-distribution (centralized, dht, unstructured P2P,etc) can still transparently collaborate while keeping a good control over their own data.