How do we determine the fine line between freedom of speech and being mindful of cyberbullying on the internet?

Teen suicide is a huge problem and its no secret that a sizeable portion of cases are caused by online harassment (or cyberbullying).

So my question is, in the interest of respect the human right of freedom of speech and expression; how should online communities deal with cyberbullying?

This is a topic I want to discuss at some point on YouTube. So as a means of research, I would like to gather some views on this issue.