A Guardian investigation has revealed that highly sensitive data held by more than 40 UK police forces — including criminal records, victim statements, and intelligence files — is stored on Microsoft's Azure cloud platform, which a 2017 official UK security assessment warned could be vulnerable to "compromise" by foreign actors and US government insiders. The assessment, signed off by Ian Dyson, who served as the national senior information risk owner for British policing, acknowledged that data could be "transmitted and stored worldwide" by Microsoft and that its extent would be "unknown," yet every UK police force ultimately migrated its data to the platform. Police authorities have maintained that contractual protections prevent unauthorised US access, but Microsoft itself disclosed to Police Scotland in 2023 that data "can go outside the UK" and that it "cannot guarantee data sovereignty" — a stark contradiction that experts say leaves some of Britain's most sensitive information inadequately protected.