When all hell breaks loose and those with cubical jobs can't take the pressure from work anymore. At this point, every member of the office brandishes a weapon of some sort (usually a gun) and creates a huge battle. A very fine way to waste time when you feel like drawing stick figures in school.
The clicking of my coworkers pen in his adjacent cubicle finally got to me, so I flipped a desk out into the hallway, and made a barricade around the water cooler and opened fire. From then on, it was an all out office fight.