The problem is that they are not actively asking permission.
They are technically legally asking permission through the EULA, but nobody reads these.
Apple do this differently, they require the user to opt in for each of their services, and except for a pitiful amount of storage, the user has to pay for a useful amount of storage. This makes the user the customer, instead of the product. They could make it easier to roll-your-own “cloud” storage by NAS, but I assume that it isn’t worth their effort.
That was what I was going to say.
That said, if someone detects some sort of data-mining plagiarism bot sucking down everything on an instance, it can be defederated very quickly.