Brian - Tone is something that is sometimes difficult to teach to our students online. Some are "tone deaf" in their online speaking, and it takes a little more time to help them to understand how their messages are "heard." I find that providing them clear examples, i.e., using their own posts to specifically point out how their words are being perceived, is very effective. I usually get a response from students like "Oh! I did not know I sounded like that, and I did not intend to come across that way." Their subsequent posts are much, much better, because they now have an awareness of their "tone" and work hard to ensure professionalism and netiquette techniques.