The glitch where you unplug the xbox connection plug thingy once you complete the challenge. For example i think last week there was blasting and relaxing and if someone had 199 kills and the challenge was 200 and he restarted the match and once he completes the challenge he unplugs his connection cable and then reconnects and ends the game and then does it over again. I think there are videos on youtube about this.
Ive heard about getting banned for this.