I have a friend I play with that anytime he thinks the enemy is being cheap or using over powered weapons (M230, Claymores, Shotguns, USAS, Knives, MAVS, Sniping, and so on) he takes out his USAS and then sends hate mail at the end of the game to the people.
If you're wondering about his kills:
http://i970.photobucket.com/albums/ae186/Gotgo/Video%20Games/ce0b3f1d.png87k tube kills.