Apple and Microsoft offer services to find your missing smartphones, while Android does not. Sony feels that there Xperia owners deserve better, so they piloted the 'my Xperia' service earlier this year and are now ready to launch the service worldwide based on their feedback from early users.Sony my Xperia will allows Sony Xperia owners to use the website to set your missing device to sound an alarm, even if it is set to silent. You can also lock down your device or wipe all the data on it if it has been stolen.
Your device will have to be on a working connection for the 'my Xperia' service to work. You can use the locate feature to track your device on a map. If your device cannot be found an email will be sent you your Google account once the device has been located by the service.You can also set your device to be locked by a four digit pin code, which will bypass any existing screen locks on your device. The service also allows you to send out a message to the phone which will pop up and if it has been found by an honest person, you can direct them to return the device back to you.
source - myXperia | Android Central