Oddbean

No, no one can link them just with the protocol, even tech savy, but relay operators probably can by watching that those npubs share the same ip, that is the same for every website, if you have an account and the an anon one on the same site, let's say Twitter, they will know if they want to.

In twitter case we assume that only Elon has access to our information and in case of law suit against my nym only under subpoena to Twitter can disclose this information! Totally different story here on nostr! It’s open to everyone and not too many of us really protected

Knowing software development, probably it's not only Elon but a bunch of devs in Twitter and they can probably know that accounts are linked. Privacy on the web is really hard. Nostr by its nature is not good for privacy, because that's not the purpose of the protocol, you can be anon, but everything is public, it's the same problem with onchain bitcoin, censorship resistance and public open protocols are almost opposite of what is required for privacy. Myself personally I have no problem with that, my only concerns are: not having important personal data leaked if there's an hack in any platform, and I don't want people to be able to easily link my many different accounts, but I am very aware that if a gov or gov agency wants to track me they will, no matter what, and that applies to almost everyone.