GARBAGNATE MILANESE, Italy — A rapt crowd gathered in this drab town in the Milanese hinterland one evening this month to hear Beppe Grillo, an Italian comedian, serve up his characteristically caustic take on the country’s politics. And he did not disappoint.

Mr. Grillo pointed to the row of fresh-faced Italians — candidates of his Five Star Movement — on the stage behind him. “These kids, they may be inexperienced — they still haven’t learned how to rig a budget, or give contracts to their friends,” he paused, his gravely voice drowned out by laughter and applause.

What they are, he said, is the product of the “hyper-democracy” that he has been promoting through his blog and the plethora of Web sites that have aggregated like-minded Italians bent on proselytizing for a new form of political activism.

It is through a deft mixture of mordant humor, righteous anger and grass-roots organization that Mr. Grillo’s movement is proving to others that it is no joke.