Well there's nothing they can really do about that, at least nothing I can think of. I do however feel that topics about sexism and or rape are things that should be discussed at home or in person so people have a better understanding on how to deal with it. Trying to make someone understand over the internet just doesn't really work as its just not the best way to reach someone.
It does work.
It's not necessarily on the people that the talk is being directed towards, but it does work on others.
More people are reading the discussion than just the people posting, and they typically come out of the woodwork later to explain how they've been changed by the discourse. It works.