Comment by crtified

I imagine this would be quite difficult in practise, due to all the subliminal factors behind a person's writing choices.

For example, as somewhat illustrated here, your personal vocabulary is a kind of fingerprint. As you mention, using a thesaurus can somewhat alleviate that, but if a thesaurus is only changing a small % of your words, then it will only have a suitably small % effect upon analysis.

To go yet further might (I suspect!) entail methods such as directly lifting and using other people's sentences to convey your own thoughts. But even then, "your own thought patterns" are still informing the manner of the post, to some extent, so over time increasingly robust analysis may still find patterns to hook into.