Economics have been one driving force, with growing income inequality, high unemployment and recession-driven cuts in social spending breeding widespread malaise. Alienation runs especially deep in Europe, with boycotts and strikes that, in London and Athens, erupted into violence.

But even in India and Israel, where growth remains robust, protesters say they so distrust their country’s political class and its pandering to established interest groups that they feel only an assault on the system itself can bring about real change…

Increasingly, citizens of all ages, but particularly the young, are rejecting conventional structures like parties and trade unions in favor of a less hierarchical, more participatory system modeled in many ways on the culture of the Web.

In that sense, the protest movements in democracies are not altogether unlike those that have rocked authoritarian governments this year, toppling longtime leaders in Tunisia, Egypt and Libya. Protesters have created their own political space online that is chilly, sometimes openly hostile, toward traditional institutions of the elite.