Pranking is good. Pranking in New York City is even better. These jesters with too much time on their hands decided to force segregation on the mean streets of Manhattan. You may recall "Frozen in Grand Central" and "No Pants", two events which helped create a name for these out of work thespians. The genesis for Improv Everywhere happened nine years ago when one of the founders decided to tell the ladies in the bar that he was musician Ben Folds during one late night of drinking. Ummm. It worked.
And dozens of large scale pranks later... well, we applaud his inventiveness.