Is UserExtendedProperties.GetValue user-specific or device-specific?

I'd like to use UserExtendedProperties.GetValue to associate a user with a high score table in a game I'm working on. Reading Microsoft's own API description I cannot work out whether this applies to a user (blah@live.com)开发者_运维知识库 or a physical device. Does anyone know?

Chris

---

UserExtendedProperties.GetValue("ANID") is an anonymous ID based on the user's Live ID. So, the same Live ID logged in from multiple WP7 devices will have the same ANID.