Well this could be a problem. Microsoft Game Studios upcoming blockbuster Xbox 360 exclusive game Halo 4 has been not only spotted in the wild, but fully leaked to certain websites. Postings appeared on Reddit and NeoGAF showing retail disc copies of Halo 4, as well as an image of the Xbox Dashboard showing Halo 4 ready to be played.
After some sleuthing around on popular sources for pirated games, we discovered that a full disc image of Halo 4 Disc 1 - the disc containing the single-player campaign - is available to download and burn to a dual-layer DVD, enabling you to play it on your Xbox 360 provided the DVD drive has received certain modifications. The image is approximately 8 GB, and the description states Disc 2 containing the multi-player portion of the game will be uploaded later. Update: Disc 2 is also now available.
Microsoft responded to The Examiner on the claims of a Halo 4 leak:
We have seen the reports of Halo 4 content being propped on the Web and are working closely with our security teams and law enforcement to address the situation.
However, no law enforcement team will be able to stop the force of the internet now that the game has leaked, as it will surely spread like wildfire. To make matters worse this leak has occurred a full three weeks before its launch on November 6, so naturally spoilers are going to be available soon for the entire campaign which can't be accessed by legitimate paying customers.
It is common for Xbox 360 games to be leaked before their release, although a leak this far before is rare. Keep in mind, for those people attempting to pirate a copy of the leaked Halo 4, that playing leaked games before their release can result in your console being permanently banned from Xbox Live.