It seems to mean that Bob's free hosting service has to be a relatively benign and permanent institution like ICANN, and not some ropey old operation like Photo

It seems to mean that Bob's free hosting service has to be a relatively benign and permanent institution like ICANN, and not some ropey old operation like Photobucket. Others on this thread are talking about Decentralized IDs, https://en.wikipedia.org/wiki/Decentralized_identifier https://en.wikipedia.org/wiki/Decentralized_identifier . Looks like those are stored in several competing systems. There's a blockchain one, a Chinese one that wants to know your real name, and a Microsoft one that wants to store your photo. This all has, uh, implications, which sound much less liberating than this at:// protocol does at first.