There was a post a long time ago on HN on how to taint your FB data over time so that it's difficult to tell where your real data stopped and your fake data began. I can't find it now, but part of the advice was don't replace your real data with gibberish, but rather with non-gibberish - public domain texts for example, or better yet AI generated text). And don't do it all at once but spread it out over a year or so.