Comment by Schiendelman

Consolidating your online activity to a single ID is a bug.

1. It enables correlation, tracking, and stalking across sites.

2. It makes people vulnerable to being locked out of that single-ID provider.

3. It makes people vulnerable across multiple services to a compromise of that single-ID provider.

4. It risks alleged abuse at any one service relying on the single-ID provider causing problems with other services, or the SIDP itself. Reputation attacks, Joe Jobs, and the like become attack vectors.

5. In the specific case of Apple, the represented population is small enough that sites relying on it would exclude a huge number of people, if there were no other alternatives.

I'm of an age and from a time in which one didn't use one's real name online, with very rare exceptions, and in which compartmentalising activities into different independent services. Service consolidation, where a small set of ogolopolistic actors snap up previously independent companies, and then decide to forcibly integrate those services, is yet another problem. One of the highest-voted HN submissions I've been associated with was my own report of this happening, 13 years ago, on Google+: <https://web.archive.org/web/20111015105327/https://plus.goog...>.

Online identifiers serve multiple purposes. I don't mind having a persistent identity as "dredmorbius" or occasionally "Doc Edward Morbius" (I've deliberately avoided using "Dr." for some time to avoid falsely claiming any unwarranted credentials). But where I don't care to have that association made, I have, or create, other independent aliases.

My general feeling is that ID systems should be at a minimum-viable-level basis, and largely a separate consideration from another often-conflated aspect, reputation.