This chapter explores the practice of crowdsourcing in global governance as a tool of multilateral diplomacy to interrogate its exact role and place in the decision-making processes. It investigates the case of the online cultural diplomacy of the International Commission of Museums (ICOM), focusing on the 2019 crowdsourcing campaign delivered by the ICOM’s Standing Committee for Museum Definition, which aimed to collect public contributions to re-define the museum agency in the 21st century. The chapter draws on media discourse analysis of the public debates concerning the new definition and applies content analysis of the 268 definitions submitted by the public to the ICOM’s official online platform. It also features interview insights from the MDPP Committee Chair. Based on key findings, the chapter argues that in the context of ICOM, multilateralism 2.0 remains a desirable vision rather than a reality.