Ads that think they know you - including your politics

Examples
Date

The New York Times picked 16 categories (like registered Democrats or people trying to lose weight) and targeted ads at people in them. They used the ads to reveal the invisible information itself, noting that it is a "story of how our information is used not just to target us but to manipulate others for economic and political ends — invisibly, and in ways that are difficult to scrutinize or even question."

The article illustrates that even though data providers don’t have people's voting history, but they can still guess whether an individual is likely liberal or a likely conservative. Acxiom is one data provider making predictions about people. 

https://www.nytimes.com/interactive/2019/04/30/opinion/privacy-targeted-advertising.html

Writer: Stuart A. Thompson

Publication: New York Times