Creative apparently has a patent on a shadowing technique that appears to have some similiarity with id Software's soon-to-be-available DOOM3's shadowing technique (story). Now, without attempting to raise any controversy on this matter, this reporter thinks that software patents in general are a Bad Thing. It is a little suspicious that Creative posted about their technique on their company's developer forum first. To have later filed a patent and then challenge id Software is in this reporter's opinion inexcusable. This is tantamount to blackmailing game developers -- inventing a technique, talking about it before filing a patent that hasn't been published and then telling a game developer that there is some infringement is just unethical behaviour.
News source: Beyond3D