We respect the opt-in/out user preferences exposed by Mastodon. The default settings is up to your Mastodon operator and can be found in Preferences > Preferences > Other > Opt-out of search engine indexing.
We honor every delete request received by Mastodon instance's public stream. A post deleted on your profile is deleted from FedSearch.
After opting-out you might want to remove your posts from the search engine. A simple post with the hashtag
#RemoveMyContentFromSearchEngines will remove every data linked to your profile from the search engine.
Make sure you're opted-out before or you will get indexed again.
Your best way is to change the default opt-in/out settings for your new users. If you wish to opt-out your server regardless of your user's preferences, feel free to contact-us for exclusion.