It is always a good idea to disable automatic logins, so a user must enter a password to gain access to your Mac. This by itself does not make your data 100% secure as they can still access your data by removing the hard disk, but it is likely to deter the casual thief.
If you lose your notebook and you are lucky to have someone honest finds it, they need a way to contact you. Even though you may have Find you Mac enabled, your Mac has to be within range of a “known” (connected to) Wi-Fi Network, before it can be located. So Find your Mac may not be able to help your recover your notebook.
With OS X Lion and Mountain Lion, Apple gives you the ability to have a login / lock screen message that you can configure to enable someone to get in contact with you, if they find your Mac. In this short article I will explain how you can set this up.
Below is an example of a login screen message:
To Set a Login and Lock Screen Message in OS X Lion and Mountain Lion.
Open up System Preferences and click on the “Security & Privacy” icon.
Note that for the lock screen message to be displayed you also must have the ‘Require password’ feature turned on in the Security panel.
Select the “General” tab and then click the little lock icon in the lower left corner of the window, enter the admin password when asked.
Check the button next to “Show a message when the screen is locked” and type your login and lock screen message in the box that appears.
Click the lock icon again to set the changes and then close System Preferences.