Technology giants today preside over vast troves of user data that are heavily mined for profit. The concentration of such valuable data in private hands to serve mainly commercial interests must be questioned. In this article, we argue that if data is the new oil, Big Tech companies possess extensive, encompassing and granular data that is tantamount to premium oil. In contrast, governments, universities and think tanks undertake data collection efforts that are comparatively modest in scale, scope, duration and resolution and must contend with ‘data dregs’. Viewed against the backdrop of the COVID-19 pandemic, this sharp data asymmetry is unfortunate because the data Big Tech monopolizes is invaluable for boosting epidemiological control, formulating government policies, enhancing social services, improving urban planning and refining public educa- tion. We explain why this state of extreme data inequity undermines societal benefit and subverts our quest for ethical AI. We also propose how it should be addressed through data sharing and Open Data initiatives.