Using a login banner with FileVault 2
In a number of workplaces that require the use of encryption, there is often an accompanying requirement for a login banner that shows an Acceptable Use Policy, legal warning or other important information that the user must accept before logging in. While there isn’t the ability to set a login banner at FileVault 2’s pre-boot login screen at this point, you can leverage Lion’s built-in functionality to display a policy banner that must be accepted before the login process can complete. See below the jump for more details.
To set the policy banner, copy a PolicyBanner.txt, .rtf, or .rtfd file with the text to be displayed into /Library/Security/ and the policy banner is set. Now when a user logs in at the pre-boot login screen, they will be required to acknowledge the dialog before they can access their account.
For example, I’ve created this PolicyBanner.rtfd document for a fictional company and copied it to /Library/Security/.
Now that the policy banner has been set, restart and log in with your account at the pre-boot login screen.
After putting in your password, but before your account’s desktop appears, you will be required to click Accept at the following window.