From Tastefully Offensive:
The team from the British film company Realm Pictures created a live-action first-person shooter zombie game in their garden and studio, then invited unsuspecting people from the online chat website Chatroulette to control their actions as they navigate around various scenarios and battle zombies with modified Nerf guns.
The comments by the people watching are great. "Could it be a lion with a thorn in its paw?" I wish they'd gotten a few drunk people. In fact, there's got to be outtakes, right? People who they edited out. I'd love to see who didn't make the final edit and why. Then again, this is Chatroulette. Every third person they connected with was probably just some guy with his dick on the screen.
Realm also did a cool little behind-the-scenes video to show how they put it all together.