Remember, Gandhi took down an empire.
Seriously, the protestors can overwhelm things. How many have been arrested since the start of it all? They all have to go through the system, every last one. This is the system, by the way, already strained to the limits fighting prohibition. Jails are full, court rooms crowded. No room for thousands more. So make them deal with thousands more. The NYPD is paying out shitloads of money in overtime. Occupy will work if it keeps on trucking. Keep getting arrested, and when they release you, come back and get arrested again. Keep the riot police on the streets constantly. Remember, these authorities have to pay to fight you. So make them pay. Keep them paying. Remember, the economic injustices you rage against have also made the government institutions who oppose you broke.
Nonviolence is the best weapon and cannot be resisted indefinitely.