How do we know who we are talking to here at PC?

A worry that crops up in my mind is that there may be researchers, psych students, psychologists etc posing as having mental health difficulties here in order to collect data. Are we all lab rats here? Being experimented on.

Sometimes I'll read a post and 'feel' that the poster is just trying to get a reaction so they can write it down in a little black book. X-person has x-disorder and reacted this way.

Am I being paranoid? Or is this a well-founded fear? I guess even if there were people doing experiments on us here, it wouldn't really matter? I don't know, I just want it to feel safe on the internet. Might be asking too much...