Occupy Boston posted a video of what happened when Newt Gingrich appeared at the Harvard Kennedy School of Government on November 18, 2011.
I have remixed it to reduce it to its essence.
It helps to understand what a mic check is if you have attended an Occupy movement event. The mic check is used to wake up the audience to the fact that the people’s mic is about to be used. The people’s mic is used to make sure a large audience hears the speaker even though the actual sound system may be weak or non-existent. The speaker talks in sound bites with pauses in between so that those who can hear what the speaker said can repeat it loudly and in unison so that everybody will hear what was said. It is very effective at a large gathering outdoors.
In the use shown here, it is quite effective to overpower someone who has a real sound system.