Facebook data reveals far more about us than we realize.
Michal Kosinski showed in 2013 that using Facebook data could accurately predict sexual orientation, ethnicity, personality traits, intelligence, happiness, addictive substances use, parental separation, age, and gender. The model even managed to separate between Democrat and Republican in 85% of cases. This research demonstrates how powerful social media data can be for profiling individuals, which contributes to why people feel uncomfortable when they don’t know how their data is being used without their knowledge.
— WhatsApp: We Should Discuss What Our Data Is Used For, Not Who Has It · Forbes