They care if you break theirs
Xfire AUP:
Quote: "l. Copyright or Trademark Infringement. Using Xfire to transmit any material (by email, uploading, downloading, posting or otherwise) that infringes any copyright, trademark, patent, trade secret, or other proprietary rights of any third party, including, but not limited to, the unauthorized copying of copyrighted material, the digitization and distribution of photographs from magazines, books, or other copyrighted sources, and the unauthorized transmittal of copyrighted software."
Edit:
The program IS copyrighted
Edit2:
Quote: "1. Can I use stuff I make in Magic FPS in commercial products?
Yes. Not only can you use them in commercial products, but you can use them in commercial segment / model packs. That's right, make your own models, import them in Magic FPS or make them in Magic FPS from scratch and sell them as your own work, because they are your own work.
You just can't sell or distribute Magic FPS itself without permission from the author."
Please show us your permission
Microsoft isnt evil, they just make really crappy operating systems -- Linus torvalds