In planning any large-scale sporting event, organizers have to take security needs into consideration. Any time you combine thousands of people in a confined space with heightened emotions and flowing alcohol, there’s at least the chance that some individuals will be tempted to cross the line of polite behavior or even public safety, so it’s always a good idea to have a few security guards or uniformed police officers on hand.
Or, as shown in this awesome time-lapse video filmed outside a stadium in Chiba Prefecture, the giant robot from Patlabor.