If you think a papercut is bad, imagine how much worse a shot to the chest with a cardboard shotgun would be.
Cardboard Warfare is a tale of treachery and conflict, as a fatal betrayal turns a meeting between two military forces turns into a bloody and brutal battle. The action soon escalates as snipers, tanks and guys in trench coats with miniguns join the fray. But there's a twist: As the name suggests, every single weapon, from assault rifles to grenade launchers and an even M-1 Abrams tank, is made of cardboard.
Filmmaker "pwnisher," also known as Clinton Jones, a digital media artist from California, said that the movie took a month and a half of planning, filming and editing, not to mention creating the cardboard weapons. It's a silly concept, but it's executed wonderfully, and the special effects are incredibly impressive. There are worse ways of spending three and a half minutes.
Source: Geeks Are Sexy