If a user loses a computer or mobile device that has an open connection to that user's Google Apps account, or maintains cookies that permit a connection without first entering a user name and password, that Google Apps account is potentially exposed to anyone who has possession of the computer or device.

To prevent unauthorized access to an account, you can reset the sign-in cookies for that user, which has the effect of logging out that user from all current HTTP sessions, and requiring new authentication the next time that user tries to initiate an HTTP session to log in to Google Apps.