Research professor Heikki Ailisto told CNN that the system involved fitting electronic devices with sensors, which monitored their owners' walking styles.
Because devices such as mobile phones and PDAs were often kept in pockets or belt clips, the sensors actively monitor the way the owner walks when the device is used for the first time.
Data collected about the way a person walks is saved in the sensor's memory, as the system learns your walking style. This process takes about one day. After this, the system can decide if an item has been stolen, and locks that item out if it believes it to be so.