Conflicting Privacy Preference Signals in the Wild
This addresses privacy ambiguity for web users and policymakers, offering incremental empirical insights to inform legal debates.
The paper tackles the problem of ambiguous privacy preference signals from users, such as Global Privacy Control and Do Not Track, by providing the first empirical evidence that these signals are sent in the wild and that browser-stored preferences reliably predict web dialog choices, with findings showing that most users adopting these standards block popular cookie dialogs.
Privacy preference signals allow users to express preferences over how their personal data is processed. These signals become important in determining privacy outcomes when they reference an enforceable legal basis, as is the case with recent signals such as the Global Privacy Control and the Transparency & Consent Framework. However, the coexistence of multiple privacy preference signals creates ambiguity as users may transmit more than one signal. This paper collects evidence about ambiguity flowing from the aforementioned two signals and the historic Do Not Track signal. We provide the first empirical evidence that ambiguous signals are sent by web users in the wild. We also show that preferences stored in the browser are reliable predictors of privacy preferences expressed in web dialogs. Finally, we provide the first evidence that popular cookie dialogs are blocked by the majority of users who adopted the Do Not Track and Global Privacy Control standards. These empirical results inform forthcoming legal debates about how to interpret privacy preference signals.