There ARE other means of expressing their views, and they are vile and despicable. But rights go to everyone, not just people who say things you don't like.
Actually, I believe you or I could probably draw - and agree to - a line on this issue on what would be acceptable. The problem is that many others would not agree with our lines. And what makes our lines better than others? At the end of the day, people move on and only a government agency could enforce such a line. Government being the corruptible entity it is, that line would change over time and influence. Therein lies the problem.