OS X Lion: Set your Mac to log out when not in use
You can set your computer to log out after a set period of inactivity. This helps ensure that your information is secure when your computer is unattended.
Important: Save any documents you changed and close any applications that may present a dialog before closing. If any dialogs for unsaved documents or open applications appear when you log out, your computer will not finish logging you out until you respond to the dialog.
- Choose Apple menu > System Preferences, click Security & Privacy, and then click General.
- Click the lock icon to unlock it, and then type an administrator name and password.
- Click Advanced.
- Select “Log out after ... minutes of inactivity.”
- Set the amount of time of inactivity before the system automatically logs out.
- For added security, select “Require password ... after sleep or screen saver begins” and choose the amount of time before a password is required.