if a games copyrighted then no.some would call it stealing the game,some would call it breach of copyright,some would call it piracy.
The older the game/movie the less chance you have of twats like the RIAA, MPAA, tracking your IP Address. But I think it should be the uploaders who should get charged not the downloaders. But these people will go after downloaders instead, why? Because more downloaders than uploaders = more suing = more money. I remember a few Halloweens ago I wanted to see what all the hype was about Paranormal Activity. I only downloaded about 30% just to see a clip, then I deleted it right away because it looked like crap, however I should have been more careful because the movie wasn't even out yet. Yet I still got a letter from my ISP. So you’re still taking a chance, but the worst these guys can really do is just give your ISP a letter to issue a warning to you. With an "old" game like COD 4, I'm sure you'll be fine, since they'll be focusing most of their attention to newer games like COD:Body Odour (Black Ops). But I don't think we're allowed to embrace piracy on this website, so you didn't hear it from me ;D.