From User Insights to Actionable Metrics: A User-Focused Evaluation of Privacy-Preserving Browser Extensions

The rapid growth of web tracking via advertisements has led to an increased adoption of privacy-preserving browser extensions. These extensions are crucial for blocking trackers and enhancing the overall web browsing experience. The advertising industry is constantly changing, leading to ongoing development and improvements in both new and existing ad-blocking and anti-tracking extensions. Despite this, there is a lack of comprehensive studies exploring the set of user concerns associated with these extensions. Our research addresses this gap by identifying five user concerns and establishing a privacy and usability topics framework, specific to privacy-preserving extensions. Also, many of these user concerns have not been extensively studied in the prior works. Therefore, we conducted an extensive literature review to identify shortcomings in the current benchmarking methodology. This led to the development of new techniques, including experiments to measure newly identified metrics. Our study reveals eight new metrics for privacy-preserving extensions that have not been previously measured. Additionally, our study enhances the measurement methodology for two metrics, ensuring precise results. We focus particularly on metrics that users commonly encounter on the web and report in Chrome web store reviews. Our goal is to serve as a foundational reference for future research in this field.