A group of people who gather at a predetermined time and place to perform a silly prank such as yelling at the top of their lungs for 30 seconds and quickly dispersing before the police arrive. Using cellphones, the flash mob can change its venue if the first one has been compromised. Why do they do this? Because they can!

Spontaneous, Fast Communications
The flash mob can be quickly organized by e-mail, blogs, texting and social networks, and messages can be forwarded several times to increase its size. Bill Wassik, senior editor of Harper's Magazine, claimed to organize the first successful flash mob in the summer of 2003 in New York. A hundred people gathered in Macy's rug department to shop for a "love rug," saying they all lived together and made purchases only as a group.