[fragmede]

This seems like a good place to drop Blue Sky's RFC on contact list sharing. Basically, they're got a way that you can share your contact list without sharing your contact list.

Through the magic of cryptography, there's now (maybe) a way to "encrypt" your contact list, upload it, the server can then find your contacts without decrypting it, and connect you with them.

That's not remotely technically accurate a way to describe what is happening under the hood, but the point is, you can share your contact list without sharing your contact list.

This magic is in RFC status from Blue Sky here: https://docs.bsky.app/blog/contact-import-rfc

[d1sxeyes]

Signal solved this years ago: https://signal.org/blog/private-contact-discovery/

[jwr]

Signal doesn't share your contact list. WhatsApp does, and this will not get "fixed", because it is done on purpose. It's the reason why Facebook paid $19 billion or so to buy WhatsApp, and from what I understand it's the main reason why Facebook/Meta keeps maintaining and developing the app.

That contact list is a huge deal if you consider how, connected to other data leaked by people using Facebook, Facebook Messenger, Instagram or other Facebook properties, it lets Meta know so much about you. For example, do some of your contacts use Messenger with location information? Do they often travel to the same location, which is a school? You likely have kid(s) in the same school as they do. It's scary if you consider the implications.