i'm pretty sure if the company of a game wanted to pull screenshots from Gamespot or something they have all the legal power to do so. hell, konami made youtube pull down the entire set of mgs4 walkthrough videos a few days ago, but then again it's KONAMI so perhaps it would be different for obscure companies. i don't know!
yes it is completely in their power if they so wish to do this. Companies have control over this stuff basically, and if you are making a profit off of it and they don't like that, they can easily sue, and will most likely win.
I was doing a really low-key project with Guild Wars' skill icons, and I had to ask permission, even if I wasn't making profit off of it. It's part of the ToU (or twas that EULA). They let me do it because I wasn't making a profit off of it, but still. These guys are, and these companies aren't going to take lightly to that.
EDIT:
Also GZ, the sites like IGN etc, are claiming exclusive ownership of the screen, but they are not plagiarizing, ie: calling it their own work. These guys have taken works and ideas from other people and claimed it as there own work (at no point do they mention they have used works from other games, nor do they have the permission to do so).