[profinger]

You're still using their engine and their world. Just because I bring a dish to someone's house doesn't mean I own it. (Of course, in this case, you own the house and you're bringing the dish.. so.. doesn't really work as well)

Of course, this goes back to what was posted last week about true ownership of products (John Deere issue). I'd say you're still right because we've already paid them for their portion of it by buying the game. Not to mention, they'd likely make more money because people have to buy it to use your content.