Call of Duty: Black Ops Easter Egg - Nuketown Mannequin secret

In the map "Nuketown," if all the mannequins' heads are shot off within 15 seconds of the "game start," the big emergency sirens begin to play "Sympathy for the Devil" by the Rolling Stones.

Note: Only the mannequins within the playable area need to be decapitated, but the mannequins re-spawn in different areas each round, so it is very difficult to accomplish without a group of about 10 players all collaborating.