Cambridge Analytica's Ad Targeting Is the Reason Facebook Exists

"“You have to proceed on the assumption that this information has been extracted from you,” Woodrow Hartzog, author of Privacy’s Blueprint: The Battle to Control the Design of New Technologies, told me on the phone. “Cambridge Analytica used an information extraction technique that was well-known to technologists for years. The implications of this debacle is about crystallizing the threat about how dangerous the information ecosystem is.”"