Netherlands based website ( is passively tracking BT devices in some areas and posting collected data in the site.

Description from the site itself “I then set up 5 locations with a little USB bluetooth stick in each location to collect data. There has to be an internet connection at those locations. Therefore I am using locations where my family and friends live. They ‘lend’ me the space and the bandwidth. To keep the budget low I am using Capio’s (Windows CE powered terminals). By reprogramming the Disk on Chip module inside I could run Linux (DSL) on the device and script it. The data collected would be sent to and processed in a central database (running MySQL). The end-result is what you will see on these pages.”