Using Password Protection
You can set passwords for your Mac in several places—keeping in line with the concept of layered security. The first place is for your user account, which is what sets up the first barrier for a data thief. You can then set passwords for other layers of your Mac's security barrier, from application access to file sharing privileges.
Setting the user account
When you set up your Mac, you set up a user account. (Chapter 25 covers the user account in more detail.) And you were asked to give it a password, this password is required to log in to the Mac, as well as to install software and make other changes that could compromise OS X. You also can attach your Apple ID—that username and password you use with the iTunes Store and Apple's other online stores, as well as with iCloud—to your Mac so you can use it to log in should you forget your user account information.
Take a minute and think whether the Apple ID password and, if you set it, the user account password, are strong enough to protect your Mac's contents should it get lost or stolen. If not, change them.
To change the user account password, go to the Users & Groups system preference and unlock it by clicking the Lock icon button (the golden padlock icon) and entering your password, if you have one. Then select your account from the list at left, and click Change Password. A settings sheet is displayed in which you type a new password, as Figure 24.1 shows. (You have to type the old one as well, to ...