The protests in San Francisco were not all of a piece; not everyone was out there blocking traffic. Here is a column from Joan Ryan in the SF Chronicle:
http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2003/03/21/ED278582.DTL
I am fine with protest and have protested myself recently. but I am not keen on disruption of "business as usual", for many reasons. It is too much of a bludgeon and goes from self expression to interference with others' rights. In some instances I am a strong believer in the institutions that are shut down, such as universities during the Vietnam war protests. I am a strong believer in the life of cities, and don't think chaos does the life of the city any good at all.
Further, as a practical point, I don't think disruption is as effective as peaceful non-provocative protest, and that it diminishes any good the protesting might have accomplished before.