Doc in the Box has a few parting thoughts as he leaves the Mojave Desert enroute ultimately to his new assignment in Iraq. Perhaps his best point is about freedom of speech and the need for mutual respect for it to really work. I thought I'd add my two cents.
I'm of the opinion that the Founding Fathers weren't all that into noise pollution or having once-read pamplets littering the streets. That's all speech is without one critical addition: a receptive mind to consider the content. It was that part of the equation that was the focus of the 1st Amendment, not the producer, but the consumer. How can I as a citizen make the best possible choices for myself when I don't know what all of the options are? I can decide for myself what is worthwhile once I have heard it. Everytime you see a speech by someone unpopular get disrupted by protesters, consider that it was the right to decide whether the speaker had a point or not was violated for every member of the audience.
Of course we have freedom to speak (or write). It would all be so much noise, however, without the other person's right to hear it and maybe be swayed by it. That is what the protester fears.