Fortune, December 11, 2015:
Ted Cruz’s Secret Weapon: Your Facebook Likes

“…Cambridge Analytica’s data seems to come from a Cambridge University professor named Aleksandr Kogan, who started conducting a large-scale personality survey in 2014. He relied on Amazon’s Mechanical Turk service to find people who wanted to participate in the study in exchange for compensation.

Kogan’s company paid people $1 to take the study and give access to their Facebook (fb, -6.53%) profiles, which would be automatically scoured for data like name, location, and gender, and Facebook likes.

But people who have never taken a Mechanical Turk survey might find themselves in the dataset, because Kogan’s company also captured the same data for each respondent’s friends. The vast majority of those contacts never gave Kogan permission to use their Facebook profiles.

http://fortune.com/2015/12/11/ted-cruz-facebook-data/