While reading some websites, articles, youtube videos regarding disc scratching on Xbox 360. I found this on http://support.xbox.com regarding their Disc Replacement Program.

But still, it is not satisfying to know that you have to pay your replacement disc if you apply the program. I mean, c’mon you bought your 100% original disc then get scratched by your very own gaming console unit.

Here are some lab (and conventional living room environment test) that the xbox 360 really scratch disc even on its standard operating state.