arg I love their songs, but they are too diva... but yeah, I think Guitar Hero should've asked them...
Yeah, sad to say, (or not) that if they had given permission to allow the song to be made as a cover, there's not much I can see legally that would be done because it turned out to sound just like the band's song. There must be something else to this case or else really there's nothing to stand on and the case should be dismissed.
