Patent ID: 6968565

Claim:
A system for identifying a content observer who views a content display device at a content display site, comprising: a sensor for acquiring data regarding an aspect of the environment of the content display device, wherein the presence of the content observer in the vicinity of the content display device when the content observer is observing the content display device can be detected from the data acquired by the sensor; means for processing the data acquired by the sensor to produce data identifying the content observer; and means for preventing unauthorized access to the data acquired by the sensor and/or the data produced by the processing means; wherein the means for preventing unauthorized access comprises a filter configured to ensure that only a subset of the acquired data that was or could have been used by the processing means to produce data identifying the content observer and/or only a subset of the produced data identifying the content observer is stored; whereby the content observer's privacy is protected by limiting the amount of acquired and/or produced data that is stored and potentially subject to being accessed without authorization.