As an answer to the obvious legal challenges of ID-based, cross-media deduplication (currently greater than those faced by third-party cookies), Google Chrome’s Privacy Sandbox, and its related W3C Working Group, provides a framework for advertisers and publishers to leverage a browser-level interest graph while preserving anonymity, through the use of aggregate data and minimum audience thresholds. As key drawbacks, there is little control on the consumer side, and local storage could result in data leaks when coexisting with either shared-identity, third-party cookies, and platform-specific IDs or walled gardens. We will address these and other issues from a legal perspective (ePrivacy + GDPR, mostly), and your humble host (Sergio Maldonado) will be on his own for this particular mission. References: The State of Cookieless (on Medium)