If you run a Mastodon server, you might want to switch on "secure mode" also known as "authorized fetch":
鉃★笍 https://fedi.tips/authorized-fetch
When it's active, it makes your defederations more effective by preventing blocked servers from accessing your server's posts.
There's a good unofficial article describing what it does at https://hub.sunny.garden/2023/06/28/what-does-authorized_fetch-actually-do
It used to have a reputation for breaking compatibility, but I've been using it for several years and haven't encountered any problems.