Chat sessions on atproto apps are not generally public. For example, the Bluesky app has private chat and Germ (https://germnetwork.com/) is an E2EE messaging app built on atproto as its identity system.
Regarding the open data— we do believe that anyone should be able to publish in the open, and building should be permissionless much like the web. But we don't think all data should be public, and clearly there is strong demand in the world for private spaces.
The community is working intently on bringing permissioned data to AT Protocol, and there are already several working examples out there illustrating different approaches. The head of protocol at Bluesky, where I also work, has been publishing his views on where permissioned data is heading: https://dholms.leaflet.pub/3mhj6bcqats2o
Regarding the open data— we do believe that anyone should be able to publish in the open, and building should be permissionless much like the web. But we don't think all data should be public, and clearly there is strong demand in the world for private spaces.
The community is working intently on bringing permissioned data to AT Protocol, and there are already several working examples out there illustrating different approaches. The head of protocol at Bluesky, where I also work, has been publishing his views on where permissioned data is heading: https://dholms.leaflet.pub/3mhj6bcqats2o