A highly de-centralized one, with information joined together across services only after authentication, authorization, and a lot of artificial identifiers. Or

A highly de-centralized one, with information joined together across services only after authentication, authorization, and a lot of artificial identifiers. Or at least, in a context where the people driving product decisions place a high priority on security. In reality, we're in the world you hypothecate right now. Centralization is really convenient for a lot of uses, and security advocates are rarely in a position to impose the kind of privacy controls the rest of us might like. And the average people who buy services LOVE the convenience enabled by centralization - until there's a breach, and they disapprove for a few days.