Actually text posts can be used to personally identify users, given you have access to enough written words from this person to build a profile of their writing

Actually text posts can be used to personally identify users, given you have access to enough written words from this person to build a profile of their writing style. It's been used to track and identify people. IIRC it's also been used in attempts to impersonate people. So one can argue that text posts are personal data that can be used to identify them, but I suppose this is the kind of thing that is up to the court to decide.