The use of data is fundamental for financial markets to work efficiently. Market actors, including financial service providers (FSPs), customers, and regulators collect data for their varied needs. The vastly increasing quantity of data generated every day enables personal data and data from multiple sources to be combined to support the delivery of financial services. This data may include assets and debts, where we travel, what we do, what we purchase, which can in turn reveal sensitive information about us, such as medical conditions and treatment. This presents both opportunities and risks.