Analyzing Privacy Policies Using Contextual Integrity Annotations

In this paper, we demonstrate the effectiveness of using the theory of contextual integrity (CI) to annotate and evaluate privacy policy statements. We perform a case study using CI annotations to compare Facebook's privacy policy before and after the Cambridge Analytica scandal. The updated Facebook privacy policy provides additional details about what information is being transferred, from whom, by whom, to whom, and under what conditions. However, some privacy statements prescribe an incomprehensibly large number of information flows by including many CI parameters in single statements. Other statements result in incomplete information flows due to the use of vague terms or omitting contextual parameters altogether. We then demonstrate that crowdsourcing can effectively produce CI annotations of privacy policies at scale. We test the CI annotation task on 48 excerpts of privacy policies from 17 companies with 141 crowdworkers. The resulting high precision annotations indicate that crowdsourcing could be used to produce a large corpus of annotated privacy policies for future research.