That IPFS does NOT put data I did not explicitly requested on my storage is exactly why I feel comfortable using it compared to some other distributed storage systems where I might end up with horrific data on my system.
And encrypted data you don't have the key for is indistinguishable from random noise. 'Combined' blocks that you don't know which partner blocks are necessary for decoding are likewise useless.
You're being like a mailman handling mail - you can't look into the mail, so you can't know if you're delivering love letters, junkmail, or terrorist propaganda.
ISPs and USPS have common carrier protection, by default a home user does not.
The underlying problem here is that it’s basically impossible to distinguish between someone naively allowing strangers to use their property and someone who is trying to cover their tracks by pretending to be unaware, and the internet is full of people who will abuse any free service. If it happens once, maybe you can plead ignorance but that’s not a foundation for a robust file sharing network.
The danger is just too big, as my sibling commenter says.
If Uber Package driver delivers a package of drugs - pretty sure he won't get to jail as it will be trivial to prove he didn't put is there and had no idea.
In your mailman example, it would be like the FBI announcing exactly what the envelope looks like, uniquely identifiable, and if you encounter this letter to report it immediately or else your complicit. Or at least, that's the fear.
Yes, if it's encrypted you have no idea, but if anyone ever found out what was in it you can know who ever transmitted it. Unless everyone re-encrypts it repeatedly.. which then makes content address-ability awkward.