I've been told by somebody that they need fedi to have no search engines, because they could be imprisoned for 10 years for what they post here, in their country.
If this is the case for you, **YOU NEED TO ANONYMIZE YOURSELF, OR STOP POSTING TO A PUBLIC NETWORK**
You MUST assume that EVERY oppressive government has a copy of EVERY public post made on fedi. Period, end of story. Anybody telling you it's possible to have it any other way is lying to you.
Any "privacy" features on ActivityPub-based software, such as Mastodon, operate entirely on the honor system. Do not trust your freedom to the honor system.