Screen lock protection
Android supports screen lock protection that requires a numeric pin or pattern to be entered before the device can be used. Though Android devices currently don't encrypt the files and data, this can still be a great way to keep out casual snoopers or thieves. However, you must enter this pin or pattern every time you use your phone, or after each time the screen goes black and locks. If you find that too time consuming or annoying, consider using Unlock With WiFi. You can use it free with one Wi-Fi network.