AC-130
A type of aircraft used by the Rangers in Call of Duty: Modern Warfare 2. In Multiplayer when your hear the Ranger saying "Enemy AC-130 above!" You know shits about to fly down on you, and it's time to book it and get the fuck out of sight and run for cover!
Ranger: "Enemy AC-130 Above!"
Call of Duty Player: "RUN FO YO LIFEE!!!"