nothing illegal about it possibly, but there is the whole fact that he must have known that no one else could play the game because he'd already tied it to an account, and that would be misrepresenting the item that he had sold. If he said, selling hardcopy of ETW, CANNOT BE USED TO PLAY THE GAME, ONLY USE SO YOU DON"T HAVE TO DOWNLOAD THE ENTIRE THING, that would be a reasonable explanation of the product he was selling. I haven't seen what the seller said, but its veeeerry dodgy to sell a game like that that needs registration. I would agree with pever though in that if theres any game that needs a serial key, don't buy it used unless you want to collect it and put it on yer shelf,

unfortunately thats the way these things go, I don't believe any consumer protection laws protect us from this stuff on ebay, if it was from a physical store you would have a case, (I think thats why there is hardly any second hand PC game sections anymore in stores like EB and that, or if there is, they are incredibly old games) but you have to rely on ebay's existing protections and hope for the best I suppose.