Automatic Content Recognition (ACR) [42] is widely used for
second-party tracking in smart TVs. As shown in Figure 1, ACR
periodically captures frames (and/or audio), builds a fingerprint of
the content, and then shares it with an ACR server for matching it
against a database of known content (e.g., movies, ads, live feed).
When the fingerprint matches, ACR server can determine exactly what
piece of content is being watched on the smart TV.
https://arxiv.org/abs/2409.06203