This research explores the interaction between internal heritage personnel and the public over social media. Focusing on the phenomenon of crowdsourcing and what it means to those individuals involved with it, this paper aims to understand: to what extent, and in what circumstances, can crowdsourcing help heritage professionals protect, preserve and promote National heritage? To answer this question, the study employs a qualitative, interpretive approach, focusing on contemporary history (‘living memory’) interactions between participants of three UK Armed Forces museums and the public. Using the conceptual framework of networks of practice (Brown & Duguid 2000) as a sensitizing concept in order to gain insight into how museum personnel employ, instigate and respond to the activity of crowdsourcing, participant interviews were analyzed and coded using Grounded Theory Methodology. The findings position that crowdsourcing is not always perceived as a dedicated activity or project focused on producing a specific outcome through crowd engagement. They also challenge a contention in literature on the formation of, and knowledge exchange within, networks of practice, suggesting that rather than extending understanding of existing networks of practice, a new form of electronic network has emerged around the museum context: the network of public.