Every IPFS node advertises the content it is making available on the network. As soon as a hash is deemed an illegal number, it would be trivial for an ISP to block nodes providing that hash. Maybe no one controls the end points, but Verizon-AT&T-Comcast still own the wire.
From the docs: “information about which nodes are retrieving and/or reproviding which CIDs is publicly available.”
From the docs: “information about which nodes are retrieving and/or reproviding which CIDs is publicly available.”
https://docs.ipfs.io/concepts/privacy-and-encryption/