My understanding of "blockchain ledgers" is that it's not the case that every single byte of a ledger entry is present in the blockchain, but that some other ledger is maintained and its digest (at various points along the way) is incorporated into the blockchain.
That being the case, "the network" doesn't own these 'side ledgers.' They have owners who may well keep non-public data. Further, that the data comprising a particular digest needn't be disclosed, only that the owner of the digest vouches for the digest. For forgettable mode, said owner validates their own data, generates the digest, adds it to the blockchain, and subsequently 'forgets' the data that created the digest.
Now maybe that flies in the face of a fully public blockchain, but it allows the implementation of that which you couldn't fathom: a right to be forgotten alongside blockchain technology.
That being the case, "the network" doesn't own these 'side ledgers.' They have owners who may well keep non-public data. Further, that the data comprising a particular digest needn't be disclosed, only that the owner of the digest vouches for the digest. For forgettable mode, said owner validates their own data, generates the digest, adds it to the blockchain, and subsequently 'forgets' the data that created the digest.
Now maybe that flies in the face of a fully public blockchain, but it allows the implementation of that which you couldn't fathom: a right to be forgotten alongside blockchain technology.