Both OpenSea and Metamask have logged cases of IP address leaks associated with transferring nonfungible tokens (NFTs), according to researchers at Convex Labs and OMNIA protocol. Nick Bax, head of research at NFT organization Convex Labs tested out how NFT marketplaces like OpenSea allow vendors or attackers to harvest IP addresses. He created a listing for a Simpsons and South Park crossover image, entitling it “I just right click + saved your IP address” to prove that when the NFT listing is viewed, it loads custom code that logs the viewer's IP address and shares it with the vendor.