Bethesda has shared its side of the story in an ongoing story over why they threatened a lawsuit over a guy trying to sell an unsealed copy of the last of us on the amazon marketplace. Ryan Hupp bought the game, never opened it, and tried to sell it on amazon. He was met with a threat of legal action if he didn’t take it down. He did so, but informed Bethesda legal that what he was doing was protected under First Sale Doctrine. Bethesda has said that they do not allow unauthorized resellers to mark their products as new because they cannot verify the product hasn’t been opened and resealed and therefore cannot offer a warranty on it.
Source: Game Spot