Bill McKibben at Occupy Wall Street Rally

Author and activist Bill McKibben addressed the crowd assembled in Washington Square Park for a special session of the Occupy Wall Street general assembly. This was during the post-GA portion of the rally. As for why the crowd keeps repeating what McKibben is saying, for those that don't know, the police have prohibited all forms of sound amplification. The demonstrators have taken to using what they call the "human microphone"—speakers address the crowd in short phrases which are then repeated across the crowd as many times as is necessary for all in attendance to hear what's being said. The pipeline he refers to, right at the beginning, is the proposed Keystone XL tar sands pipeline, currently in the final review phase by the State Department.