Project Gaydar
Just by looking at a person’s online friends, you can predict whether a person is gay two MIT students found out. They did this with a software program that looked at the gender and sexuality of a person’s friends and, using statistical analysis, made a prediction. So people may be effectively “outing” themselves just by the virtual company they keep.
Their project is called Gaydar - and I would loooove to have a copy of that software :-)