Online communities can serve as vibrant hubs for collaborative innovation beyond formal organizational boundaries. Particularly through open and fluid participation, they enable knowledge exchange in previously unparalleled scale. However, this participatory fluidity also exposes vulnerabilities within knowledge work in online communities, creating a challenge of organizing for openness while protecting against abuse and malevolent exploitation. Focusing on the open-source project HackerToy —a tool enabling access to and manipulation of wireless devices—we investigate how the associated online community navigates the conflicting objectives of both open collaboration to advance the device’s features and closure to shield against misuse and illegal transgressions. Through a qualitative analysis of netnographic and interview data, we uncover ‘public secrecy’ as an organizing principle to manage the limits of open participation in online innovation communities characterized by a lack of formal organizational structures. The shared understanding “not to acknowledge what everybody knows” constitutive of public secrecy acts as a defining element of membership evaluation, guiding the community’s knowledge processes, and thus protecting against both internal and external threats. These findings advance theory on social processes that organize online innovation communities by illustrating how practices of secrecy both establish group membership and foster exploration within open innovation processes. Thereby, this study offers novel insights on the social aspect of secrecy in online innovation communities by highlighting how it not only protects but also advances knowledge.
