Games leak onto the internet all the time. Usually a week or two before they hit retail. Leaking months before release, though, that's a little rarer.
Yet a playable build of Gears of War 3 hit torrent sites late last week, representing an early look at the game's singleplayer campaign from a build of the project that's not even complete yet.
"We have seen the reports of Gears of War 3 content being propped on the Web and working closely with our security teams and law enforcement to address the situation," Microsoft told IGN.
"This content is not from a final build and is not representative of what fans will enjoy when the game launches."
While some other titles have popped up a little early in recent years - a preview build of early Deus Ex levels, an early release of Halo: Reach - it's not often you get leaked code from a game before it's been pressed onto a disc. No wonder the cops are involved.