The Roskilde Festival is one of the biggest music festivals in Europe. It takes place over eight days during the summer in Denmark and attracts well over 100,000 people every year.
In 2011, Jakob Eg Larsen and pals from the technical University of Denmark set up a curious experiment to observe the patterns of behaviour among festival-goers using Bluetooth technology.
These guys set up 33 Bluetooth scanners at various locations at the festival that recorded any Bluetooth-enabled mobile phone that passed nearby. The idea was to see how participants moved between the six different stages at the event, how this changed with the music that was on offer and how people gathered at other places such as beer halls and restaurants.