The magazine that helped launch the Occupy Wall Street movement is calling for 50,000 protesters to come to Chicago for the NATO and G-8 summits.

Adbusters Magazine is based in Canada, but has followers and fans around the world. This week it posted a tactical briefing on its website that calls for a showdown in Chicago. They want 50,000 protesters to show up on May first with tents for a month-long people’s summit. That’s nearly three weeks before the NATO and G-8 summits will begin.

Adbuster’s rally cry was news to Occupy Chicago.

“Adbusters had not contacted us prior to making this internet call,” said Evelyn Dehais, a press liaison for Occupy Chicago. “We’re excited by the possibilities of it, but we’re still figuring out internally exactly how to deal with the situation.”

Dehais said Occupy Chicago is committed to non-violent action. The adbusters posting is calling for flashmobs and shutting down unnamed corporate headquarters if their demands are ignored.

Chicago Police Director of News Affairs Melissa Stratton issued the following written statement:

“The Chicago Police Department is actively preparing to achieve two goals – to ensure the public safety of residents, visitors and event participants – and to protect the First Amendments rights of individuals who choose to exercise them. We are preparing for an event and are confident in the ability of the men and women of the Chicago Police Department to provide a quality experience for everyone involved.”