If you buy and sell an NFT that violates IP law you could be liable. Steer clear of bootleg NFT's that copy popular collections.
NFTs Govern Ownership of the Token, Not the Underlying IP Rights
Ownership of an NFT as a unique token – versus ownership of the content that such NFT may be associated with – is a critical distinction. When someone purchases an NFT tied to a piece of content, they have not automatically purchased the underlying intellectual property rights in such piece of content. Under Section 106 of the U.S. Copyright Act, a copyright owner has certain exclusive rights to reproduce, prepare derivative works of, perform, display, and distribute the copyrighted work. As a general rule, the purchase of a piece of art does not transfer all copyright in such work to the buyer. For example, when someone buys a painting at an art gallery for their home, they are acquiring the physical painting itself, which they can display, but not the underlying rights to reproduce, make derivative works of, or distribute copies of such painting.
Source: Fashion Law
Getting sued for $150k for flipping an NFT
OpenSea Just Saved Their Users Millions in Potential Copyright Damages
On July 13th, Opensea, the leading marketplace for secondary NFT purchases, delisted CryptoPhunks from their platform and threw the NFT world into a storm. Some people came to the defense of Opensea, claiming this is a good step in protecting the intellectual property rights of artists. Others bashed Opensea, because censorship and regulation can be the highest form of treason in a decentralized world. What most people don’t realize is that Opensea protected not only itself, but the people who use their marketplace from potentially huge legal repercussions.
Source: NFT Attorney