Some kind of a legal notice? Its not that hard to imagine the legal options a company will have if someone is using their IP, right?

Yes, but it's on a distributed blockchain. An immutable record of ownership and held in a wallet protected by a private key. So what does "shut it down" mean in that sense? They can go after the owner of the NFT, and the people who minted the Olive Gardens in the first place, but are they going to take down all the ETH nodes? Perhaps all the NFTs will have to be transferred to the ownership of Olive Garden, but that isn't shutting it down.

I want to ask you a framing question: have I violated anyone's rights if I tell you that I had Cheerios for breakfast this morning?