In theory I don't think this is feasible for any text that can be read by robots (eg the fediverse)

If the file containing the text is itself poisoned then maybe?

Unfortunately, Nightshade can already be thwarted by AI.

I have seen those who have left reddit put a word scrambler to work on their accounts, editing all of their comments into garbled nonsense. I'm not sure how effective that is to deter AI scraping, especially if reddit can just pull from history before the comments were edited. Also, it is a more destructive means of obfuscation because your comments will be unreadable to humans as well.

I do hope a solution comes along, though.

Attach the entire pdf of codex seraphinianus to all your texts like some ancient-nomadic child putting wolf teeth under their pillow to protect from the evil eye.