A Decade of Privacy-Relevant Android App Reviews: Large Scale Trends

TL;DR

This study analyzes 12 million Android app reviews over a decade to identify trends, topics, and sentiments related to privacy, revealing growth, geographic differences, and unexpected positive attitudes towards privacy features.

Contribution

It provides a large-scale, longitudinal analysis of privacy-related user reviews using NLP, uncovering trends, geographic patterns, and new insights into user perceptions of privacy.

Findings

Privacy reviews have consistently increased over 10 years.

Many reviews express positive sentiments about privacy features.

Reviews reveal unexpected uses, like privacy disclaimers to developers.

Abstract

We present an analysis of 12 million instances of privacy-relevant reviews publicly visible on the Google Play Store that span a 10 year period. By leveraging state of the art NLP techniques, we examine what users have been writing about privacy along multiple dimensions: time, countries, app types, diverse privacy topics, and even across a spectrum of emotions. We find consistent growth of privacy-relevant reviews, and explore topics that are trending (such as Data Deletion and Data Theft), as well as those on the decline (such as privacy-relevant reviews on sensitive permissions). We find that although privacy reviews come from more than 200 countries, 33 countries provide 90% of privacy reviews. We conduct a comparison across countries by examining the distribution of privacy topics a country's users write about, and find that geographic proximity is not a reliable indicator that nearby countries have similar privacy perspectives. We uncover some countries with unique patterns and explore those herein. Surprisingly, we uncover that it is not uncommon for reviews that discuss privacy to be positive (32%); many users express pleasure about privacy features within apps or privacy-focused apps. We also uncover some unexpected behaviors, such as the use of reviews to deliver privacy disclaimers to developers. Finally, we demonstrate the value of analyzing app reviews with our approach as a complement to existing methods for understanding users' perspectives about privacy