This panel examines how emerging technological systems and corporate data extraction practices are fundamentally challenging the rhetoric of openness that has organised digital humanities and GLAM ethics, along with many other internet communities, since the early days of the world wide web. While openness and data availability once promised democratic access to cultural materials and research findings, this framework was implicitly reliant on existing regulatory frameworks, institutional protocols, and infrastructural conditions that had managed availability, remuneration and protection of cultural materials prior to the digital age. The current, large-scale appropriation of datasets (public, semi-public, and proprietary) by technology corporations – for the purposes of training large language, image and multimodal models – has revealed how digital openness depended on these existing systems of governance and control, which are no longer functioning as designed. As legal frameworks struggle to address corporate data mining or protect cultural producers (or prosumers) and government regulatory responses lag technological developments, data creators, including digital humanists, and cultural institutions face increased risks to their intellectual labour and community materials. Is this the “end of open data,” and if so, how should data holders, cultural institutions, and digital humanists respond? To what extent have past assumptions about openness systematically disadvantaged marginalised groups, especially First Nations communities and Global South institutions whose materials were made available for extraction? How do we move beyond binary framings of open versus closed to develop more nuanced, care-based approaches to digital cultural materials? In what ways can our communities learn from other disciplines (such as social science models of data donation) and to what extent are different approaches necessary?