It’s an access control method, called “authorized fetch”. Rather than broadcasting the data you just announce the source of it, and then any client that wants to show it needs to negotiate with the originating server to request the data (And then blocklists and such come into play)
Say you’ve got 3 users, A, B, and C. A has blocked C, B follows A, and C follows B. Now A makes a post, B sees it in their feed and reboosts it, what does C see?
If B’s server sends the full response along, then C can see the contents of A’s post even though they’ve been blocked by A. But if all it sends is the URL of the post, C’s server needs to make a request for it (providing authentication), and then A’s server can reject it, so C sees nothing.
It’s an access control method, called “authorized fetch”. Rather than broadcasting the data you just announce the source of it, and then any client that wants to show it needs to negotiate with the originating server to request the data (And then blocklists and such come into play)
Say you’ve got 3 users, A, B, and C. A has blocked C, B follows A, and C follows B. Now A makes a post, B sees it in their feed and reboosts it, what does C see?
If B’s server sends the full response along, then C can see the contents of A’s post even though they’ve been blocked by A. But if all it sends is the URL of the post, C’s server needs to make a request for it (providing authentication), and then A’s server can reject it, so C sees nothing.