Analyzing Unnecessary Permissions Requested by Android Apps Based on Users' Opinions

Many existing mobile apps request for unnecessary permissions knowing that users often ignore permission warning messages. We conducted an online user study to investigate how users feel about permissions being requested by both free and paid Android apps. Results show that users tend to feel that free Android apps request for more unnecessary permissions compared to paid apps. Users also felt that older apps (those that are previously released and have gone through several updates) request for more unnecessary permissions than those that are newly released. Based on that observation, we surmise that many developers initially publish apps that require a small set of permissions (so that users are not discouraged from installing an app), and gradually add more permissions to their apps through updates.