[ Thanks to kiterunner for this link.
]
“Prey is an open source application that sends data regarding
the current location of your missing device. The latest version of
the application has the capability to even take pictures using the
device’s inbuilt webcam and send it to you upon request.“When your device goes missing and someone boots it, Prey will
try to send the the geographical location data of your device using
either Wi-Fi(which can be set to ‘connect automatically’) or direct
Ethernet connection.”