I do not for one minute believe those to be stress cracks, that computer has taken a fall and a big one at that.
And either you or one of your friends is responsible for it, that is no manufacturer problem, no way.
The laptop I had (being as I gave it to my girlfriend today as I got a new AW) went all around the world for 2 years, it had bangs and bruises all the way, but it didn't look anyhting lie that.
I think your trying to pull a fast one. but good luck to you