http://www.microsoft.com/games/e ... ages/gfw3intro.aspx

Anti-piracy Protection

Starting with new title releases this fall, publishers can optionally take advantage of two new methods to ensure everyone's playing with a legitimate copy of their games.

Server Side Authentication links the game license to your Gamertag. The advantage of this method is that it allows installation of the game onto any PC, anywhere — only you can access the LIVE service from the game. Server Side Authentication has no affect on offline play..

Zero Day Piracy Protection keeps games from launching before the street date the publisher has set for the game.

莫非是因为用了免CD？