yesterday I was on club penguin. I walked in to the cove and there were two green penguins. They were saying: go green save the earth! Over time a crowd gathered around them… they all turned green and started saying: go green save the earth! Suddenly one of them said: go to the plaza. Everyone started leaving. I went to the plaza. They had all gathered there! I had run in to a flash mob.
What is a flash mob? Here is the reference.com definition: A flash mob is a large group of people who assemble suddenly in a public place, perform an unusual action for a brief period of time, then quickly disperse.
And this is a video that I got off of social capital blog!