Mac OS X Display Access Warnings Message For The Login Window

I know how to display notice of a computer's ownership, to warn against unauthorized access, under Linux gnome desktop. How do I display similar message under Apple Mac OS X to remind authorized users of their consent to monitoring?

You need to use defaults command to read, write, and delete Mac OS X user defaults from a command-line shell option. You must run the following command using sudo. When your user tries to access the login window, the user sees the access warning you create. This applies to both local and remote desktop.
Open a terminal.
Type the following command:

sudo defaults write /Library/Preferences/com.apple.loginwindow LoginwindowText "YOUR Message Here"

For example,

sudo defaults write /Library/Preferences/com.apple.loginwindow LoginwindowText "Use of the system implies consent to monitoring, any unauthorized use of the system will be prosecuted."

Logout and login back again to see your changes.

Update /etc/motd

Edit /etc/motd, enter (type the command at terminal):
sudo vi /etc/motd
Add your access warning message:
Use of the system implies consent to monitoring, any unauthorized use of the system will be prosecuted.
Save and close the file.