The problems in Iran, on the surface, are the result of a disputed election, but when you dig a little deeper the real difficulty, at its core, is a conflict of beliefs. To change regimes then, there must be a change of ideas. Since the street protests are to be truly effective, you need to start a different kind of campaign. Violence is compounded to find the situation that the current regime justification for their own violent repression.
As you can go, used a system constantly as a threat as a force to change, public resistance to thwart actions? The only way to combat the current regime is to discover the ideas and beliefs that are at the root of the problem and attack at this level.