If you don't like kids playing Call Of Duty, come up with a solution, because checking IDs at the point of sale clearly isn't working. It won't stop someone old enough to buy the game from handing it off to someone who isn't old enough.
Maybe we need to check IDs at the point the game is played. If it's on a PC with a videoconferencing camera, for example, the game should be programmed not to start if:
1. The camera is blocked
2. The face in front of the camera looks too young (and has no photo ID to prove otherwise).