> All those solutions offer a way for a service-provider to just ask for a service-provider-specific persistent identity Even if working solely as advertised,

> All those solutions offer a way for a service-provider to just ask for a service-provider-specific persistent identity Even if working solely as advertised, and somehow implemented flawlessly without compromising a user's right to modify their device, I think the stated goal itself is contentious. Alt/throwaway accounts are a useful (and for some, necessary) tool for maintaining privacy. I do not want identity-bound "rationing" of certain types of online content, nor do I see elimination of "unlawful account sharing" as a positive.