For the past year and a half, ProPublica has been building a searchable database of political ads and the segments of the population advertisers are paying to reach. We did this by enlisting thousands of volunteers who installed a web browser extension. The tool shared the ads users see as well as Facebook’s details on why the users were targeted.
“We regularly improve the ways we prevent unauthorized access by third parties like web browser plugins to keep people’s information safe,” Facebook spokesperson Beth Gautier said. “This was a routine update and applied to ad blocking and ad scraping plugins, which can expose people’s information to bad actors in ways they did not expect.”
Facebook users didn’t expect to have their information exposed to Cambridge Analytica to be used in ways users didn’t expect either.