I'm afraid I don't know who moderates the Steam discussion, but yes there is a report function (which I've just used myself now the post has been pointed out: the post and some of the discussion resulting from it certainly wouldn't be acceptable on these forums).

I'll also see if I can find out for future reference who does moderate there.

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"