Lars Backstrom ('04, PhD '09) and Jon Kleinberg's work on using social-network structure to predict relationship status was mentioned in a recent New York Times Op-Ed.
The article, "'You' is the New Me", uses Backstrom and Kleinberg's research to exemplify the point, "The fact that other minds aren’t that different from our own also comes out in the new data that have been amassed online" : "A Facebook researcher and a Cornell professor developed an algorithm to predict the likelihood that a Facebook user will change status from “in a relationship” to “single” within a two-month period. In other words, Facebook might be able to predict that you’re going to break up with your boyfriend before you know it yourself — or at least before you’ve told your online friends."