That's the whole point on this NFT conundrum, right? One can post something without even have to confirm that they are the owner by rights of what they are selling. https://www.vice.com/en/article/wxdzb5/more-than-80-of-nfts-...
NFTs will find better success with items whose scarcity or uniqueness is constrained by the law or physics. An NFT proving partial ownership of a company like Apple will work because there are legal penalties to copying Apple and it's property. An NFT proving membership in a nightclub will be safe because copying the NFT's smart contract doesn't accordingly copy the physical building the nightclub is in.