Kai Ryssdal: It’s the 3rd of October, which makes this week number three of the protests that’ve come to be called Occupy Wall Street. A small-ish group of activists camped out in a New York City park has become a string of bigger street protests; there were hundreds of arrests this weekend on the Brooklyn Bridge, there are new encampments all over the country today.

Marketplace’s Eve Troeh explains how it got started.

Eve Troeh: The genesis of Occupy Wall Street might be an email from the anti-consumer magazine Adbusters; it called for actions starting September 17th. That is when activists like Isham Christie gathered. Their goal?

Isham Christie: A blossoming social movement in the United States to fight economic, political and cultural injustices.

General assembly meetings happen daily, ideally to crystallize one set of demands. But as more political and labor groups jump in, their specific goals have to get added to the mix. The group’s now so big, meetings lean toward logistics: food, dry socks, legal aid for those arrested.

No amplifiers allowed in the park, so messages go through a system called the human microphone.

Crowd: Please come to the outreach table, to the outreach table, to the…

Dozens more cities have sprouted protests. In Los Angeles, about 100 people camped near City Hall. They had to move once — due to a Hollywood film shoot. Film student Joe Briones is coordinating camera crews for the protest.

Joe Brionas: A lot of people here are the disenfranchised. They don’t have the means to get to New York — how are they gonna get there?

Which is why the name “Wall Street” might be dropped, and the movement shortened to, simply: Occupy.

In Los Angeles, I’m Eve Troeh for Marketplace.