Lol its a trick, they want people to play the single player, millions played COD4 and they found that over 80% of the people didn't play or finish the single player (they found this by seeing if players had the finish game achievement on 360, no trophies back then). Prime example most of the people in our clan has the game yet no one complained that you couldnt get trophies (you can now after today's update). That's because none of us even played the single player yet lol.