Turning on the passcode feature can prevent a thief from peeking at your iPad's data. However, for even more security, you can make your iPad automatically erase its data if someone tries 10 incorrect passcodes in a row. To turn on this data-erasing feature after you have already defined a passcode, follow these steps:
From the Home screen, tap Settings. The Settings screen appears.
Tap General. The General settings screen appears.
Tap Passcode Lock. An Enter Passcode screen appears.
Type your four-digit passcode. The Passcode Lock screen appears.
Tap the Erase Data on/off switch. If you turn it ON, a message appears letting you know that your iPad will erase its data after 10 failed passcode attempts, as shown in Figure 8-4.
Tap Enable or Cancel.
Press the Home button.