theodp writes "At MIT, an experiment that identifies which students are gay is raising new questions about online privacy. Using data from Facebook, two students in an MIT class on ethics and law on the electronic frontier made a striking discovery: just by looking at a person's online friends, they could predict whether the person was gay. The project, given the name 'Gaydar' by the students, is part of the fast-moving field of social network analysis, which examines what the connections between people can tell us, from predicting who might be a terrorist to the likelihood a person is happy, fat, liberal, or conservative." MIT professor Hal Abelson, who co-taught the course, is quoted: "That pulls the rug out from a whole policy and technology perspective that the point is to give you control over your information — because you don't have control over your information."