Despite needing to enter your root password to alter such basic things as CPU Scaling, you are not once prompted to enter it to access the Passwords and Encryption Keyring. Anyone is able to view your stored MSN, Twitter, email and Wifi passwords in four simple clicks of the mouse from the desktop.
How to reproduce:
1. Restart your computer and login. Do not enter any passwords after your desktop has loaded.
2. Go to Applications > Accessories > Passwords and Encryption Keyrings
3. Click on the 'Login' folder to drop down and view the programs that store data here.
4. Double click on something you want to look at.
5. Click Password to show some dots, then uncheck the box below the dots marked "Show password"
6. Note that throughout this whole procedure, not once were you prompted to enter in anything that verifies you are authorized to view this information.
This is a security risk, and, because it is a conscious decision for design, not classified as a bug.
Here's the related Ubuntu Forums thread:
and, a post on omgubuntu.co.uk: