That doesn't make sense. An NFT exists purely in the realm of reality. It has a real (non-fungible!) representation as 1s and 0s and it's etched into "the blockchain". That's just as "real" as the atoms that makeup a bicycle. Arguably, much less valuable, but still real. At the end of the day, the NFT is represented by atoms as well.

If you steal my bike, that's theft. If you steal my DVD collection, that's theft. If you steal my steam account, that's theft. If you steal my NFT, that's theft.