Just because you post on the internet doesn't mean its public, each company has a privacy policy, of which nobody "opted in" for LLM use either when they signed up, they may have opted in for targeted ads, but not LLMs or a virtual recreation of your likeness, skills or persona. I don't remember reading that anywhere in any TOS or privacy policy.

So, it is the exact same story, plagiarism from the plagiarism machine.