Okay, this is a fun little trick. YouTuber Master of Luck has taken to playing Call of Duty: Ghosts with the Xbox Live Gamertag "Xbox Sign Out." In a multiplayer setting like this where players are prone to shouting each other's names and the Kinect is listening for voice commands, sign-outs are bound to ensue. Even when people know what's up, they still inexplicably say the magic words.
I like that everyone who fell for the prank seemed to find it humorous. I wonder if that was truly the case, or if a bunch of genuinely angry folks didn't make it into this video.