Mozilla 2023 Analysis
Title: A Privacy Analysis of Google’s Topics Proposal
Authors: Martin Thomson (Mozilla)
Abstract/Summary: The Topics API is a second attempt — after FLoC — to find a way to provide sites with information that can be used for ad targeting based on user interests. We find that the privacy protections in the Topics API are not sufficient to provide users with confidence that they cannot be reidentified and tracked. A critique of Google’s initial privacy analysis is offered. We also examine shortcomings of the topic witness mechanism. This mechanism is intended to protect privacy by limiting access to the information provided by the API. The mechanism produces both competition and privacy problems. We conclude that Topics has significant and structural privacy challenges that are difficult to remediate.
Other: Mozilla negative position