Incident occurred after "Tour de Fat" bike and music festival sponsored by Fat Tire Brewing at Palmer Square Park in Logan Square. At the rear of the event, completely within the square, near Albany Avenue, there were fence-like barricades approximately 4' tall and 12' wide to which bikes were locked. I locked my bike to one of these barricades. I left my bike there at approximately 5pm to visit friends in the area. I returned to the park at around midnight and the barricades were gone, as well as my bike. Since it had been dark when I returned to get my bike that night, I returned to the park again the next day to confirm that the bike and barricades were indeed removed. It is possible that, at some point while I was away, my bike may have been impounded or stored at another location by the authorities while the barricade to which it had been locked was removed from the site. Since the U-lock is also missing, I do not know for sure whether or not the U-lock was cut to separate the bike from the barricade, although I suspect the lock probably was cut.