Prey is a freemium web service for tracking and monitoring laptop and desktop computers, smartphones and other electronic devices capable of running software applications, mainly intended to help in cases of theft. The service is hosted by servers on the Internet, to which an open-source software agent on the tracked computer connects. The host can signal the agent, prompting it to reply with information about its current location, and can trigger various other actions.[4] The user can log into the Prey site if the tracked device is stolen, and request information about its location.
Prey runs on most versions of Microsoft Windows (except Windows Mobile and Windows Phone), Linux, Android, OS X and iOS. The computer version of the Prey agent is written primarily in Bash, while the mobile counterparts are written in their native languages, Java and Objective-C.[5][6]
All of the client-side source code is published on GitHub and distributed under the GNU General Public License; the server code is proprietary,[7] although an open source version is available for public use.[8]
When the device is connected to the Internet after Prey has been asked for information, typically by the device's registered user after theft of the device, the Prey server asks the software agent to send location information which is, subsequently, made available to the registered user.
Location information:
When a device is to be located, usually because it has been stolen and may be used by unauthorised users, the owner logs into the Prey site and reports it as missing. The Prey server then attempts to contact the device when it next connects to the Internet, asks for its location information and, optionally, submits owner-issued commands, e.g., to lock the device.
For devices with GPS capability, such as such as smartphones with built-in GPS (satellite positioning) capability, the GPS location is used.[11]
For devices without GPS capability, and for computers unable to connect to GPS (either because they do not have a GPS receiver or because they are located indoors and, as such, beyond the reach of GPS satellite systems), if it the device has a Wi-Fi interface, the device scans for Wi-Fi hotspots (it does not need to connect to any of them) and uses Wi-Fi positioning by means of the Google Location API to obtain location information[12][13]
On devices with neither GPS nor Wi-Fi capabilities, such as most desktop and some laptop computers, Prey provides the location of the Internet server the device is connected to; although such server's location may be far from the device and, as such, of little use in pinpointing its location.