A ﬁnal, indirect source of transparency and information about the dealings of
platform companies is created by research and investigative work by third
parties, such as academics and journalists. The investigative journalism
nonproﬁt ProPublica has
into
Facebook’s advertising interfaces, successfully showing how, for example,
those interfaces can be used to target anti-Semitic users or exclude certain
minorities from seeing ads for housing or jobs (see Angwin, Varner, and
Tobin 2017a, 2017b). This work also can rely on crowdsourcing. Before
Facebook made their infrastructure for accessing advertisements through an
Application Programming Interface (API) available, ProPublica built a browser
extension that Facebook users could install to pull the ads that they saw on their
Facebook, and a similar strategy was employed by the British group
WhoTargetsMe, as well as researchers at the University of Wisconsin, who
Social_Media_and_Democracy