by Zoë Pollock
Kevin Gold explores how pattern recognition software challenges our ideas about privacy:
[R]esearchers have trained a program to identify the sexual orientation of gay males with roughly 80 percent accuracy using the self-reported orientation of their Facebook friends. Alan Mislove of Northeastern University has shown that it takes only a 20 percent participation rate among college students in filling out profile information to deduce facts—such as major, year, and dorm—about the nonresponders who simply friended others.
The software uses statistics gleaned from large data sets about how often friends tend to have characteristics in common when they are a part of a community and how often they might simply share characteristics by chance; then it combines several such probabilities into a statistically motivated guess as to whether a person belongs to a particular community. So it's not actually possible to participate in social networks without revealing anything about yourself; you reveal your interests by association.
The Dish 