This is a fascinating data visualization.
Downtown Goes Dark on Foursquare
By Sam Biddle
As saltwater poured into Manhattan, Manhattanites fled to higher, electrified ground like Wi-Fi rats. But other than tweets, we had no proof—until now. New Yorkers’ Foursquare checkins, charted by the company itself, show a massive exodus northward, out of the Dead Zone and into techie comfort.