Could teachers be given the option to create anonymous discussions where students could post to it but their name does not appear to other students? The teacher should still be able to see who posts what (appropriateness of posts etc). The teacher used the face to face instruction comparison of a gallery walk, where students walk around a class/hallway and read/view posters, then put post-it comments on them. Noone knows whos posters belong to who.
She also made the point that certain topics can get quite personal... and having them be anonymous to other students would allow for them to feel comfortable opening up more.