The building, in which project bluebox took place, had been built in 1967. Shortly after the German Reunification, all inhabitants started to move out. Almost each of them left behind a nice ceiling light in his or her flat. In the run-up to HAR2009, nine of the old lamps went into action again. After cleaning and repairing them, they were arranged as a 3×3 matrix. Now, they are showing the appropriate hacker symbol Glider, which refers the the hacker culture around free software and open source. See Wikipedia for further information..