Purview labels, tenant policies and audit logs do real work at the organisational layer. They don't act on the device as someone types, and they can't reach ChatGPT or Claude in a browser tab outside the Microsoft boundary. An audit log of a prompt records that the sensitive data was already sent.
Locke recognizes and screens Microsoft Copilot desktop, subject to supported request types, platform and settings. The Locke extension does not screen chat at copilot.microsoft.com, which uses a WebSocket. Desktop-wrapper support does not establish coverage for Copilot embedded in Word, Outlook, Excel or Teams, or for unsupported voice and realtime modes.
The risk with Microsoft Copilot
Copilot reasons over your whole tenant: documents, email, Teams. Tenant-level controls govern the channel and keep audit records, but they don't stop regulated fields entering a prompt as it's written. Desktop screening can reduce exposure on supported routes. It does not replace tenant governance or cover every Copilot experience.
How Locke helps
Locke screens the AI tools employees use beside Copilot. The Locke Extension screens ChatGPT, Claude and Gemini in the browser. The desktop app's local proxy screens GitHub Copilot and command-line agents. Locke also recognizes and screens Microsoft Copilot desktop on supported routes. The extension does not screen Microsoft Copilot browser chat; see Known limitations. GitHub Copilot is a different product and is screened.
Locke is free for one person
It runs on your device and masks sensitive data before a prompt is sent, on the AI tools it covers. Teams starts at $14.99 per seat a month.
