Previous chapters have examined the main technical approaches to privacy protection as well as key issues in the data ecosystem, including data circulation, data monopolies, and data fairness. At the root of these problems lies the opacity of data. Enhancing the reasonable and appropriate transparency of data acquisition, sharing, and usage not only facilitates the resolution of these issues but also serves as the final safeguard when they arise. For example, in cases of privacy leakage or data misuse, data transparency enables regulators to quantitatively assess the status of data collection, thereby providing technical support for addressing problems such as privacy breaches and monopolistic practices. When such issues occur, transparency in data acquisition and sharing allows regulators to determine who misused the data, where the misuse occurred, and under what circumstances—making traceability and accountability possible.