Urban Monkey Warfare occurs when a large number of crazy, possibly diseased, monkeys invade an urban area and proceed to systematically attack the human population. The humans in turn have no choice but to defend themselves, and the army is called in, turning the urban areas into large battlezones. The biggest ever Urban Monkey War was fought in Minto, NSW. The humans ultimately won, but both sides sustained heavy losses.
Urban Monkey Warfare is also the title of a song by KMFDM
"If you see a large number of crazy monkeys near your house, prepare for Urban Monkey Warfare!"