Behrendt and Sheller formulate mobility data justice as the critical framework required when movement becomes inseparable from data production, storage, circulation and ownership. The iconic idea is that being mobile increasingly means being datafied, whether through ticketing apps, navigation platforms, shared micromobility, sensors, vehicle diagnostics or environmental monitoring. The theoretical contribution is to join mobility justice and data justice, asking whose movements become visible, whose are excluded, who owns mobility data, and how access is enabled or constrained by digital infrastructures. Methodologically, the paper operates conceptually, mapping a research agenda around inclusion, exclusion, ownership, privacy, surveillance, algorithmic sorting and the mobility of data itself. Its bridge to the wider field is substantial: it connects mobilities research, STS, digital society, platform urbanism and social justice, making datafication a central terrain where transport inequality is transformed, amplified or contested.