When your instance defederates from another instance, their content can’t be pushed to you, but is there a way to stop your content from being pushed to them? (Answered: Misunderstanding)

Or have I misunderstood?

I suspect the response will be that content on your instance should always be considered public, and that you can't really stop a bad actor from spinning up fake instances or scraping your site for the data regardless, but I just wanted to confirm.