Smart TVs collect viewing data even when used as external screens

According to research involving UC3M

Universidad Carlos III de Madrid

A scientific team from Universidad Carlos III de Madrid (UC3M), in collaboration with University College London (England) and the University of California, Davis (USA), has found that smart TVs send viewing data to their servers. This allows brands to generate detailed profiles of consumers’ habits and tailor advertisements based on their behaviour.

The research revealed that this technology captures screenshots or audio to identify the content displayed on the screen using Automatic Content Recognition (ACR) technology. This data is then periodically sent to specific servers, even when the TV is used as an external screen or connected to a laptop.

"Automatic Content Recognition works like a kind of visual Shazam, taking screenshots or audio to create a viewer profile based on their content consumption habits. This technology enables manufacturers’ platforms to profile users accurately, much like the internet does," explains one of the study's authors, Patricia Callejo, a professor in UC3M's Department of Telematics Engineering and a fellow at the UC3M-Santander Big Data Institute. "In any case, this tracking—regardless of the usage mode—raises serious privacy concerns, especially when the TV is used solely as a monitor."

The findings, presented in November at the Internet Measurement Conference (IMC) 2024, highlight the frequency with which these screenshots are transmitted to the servers of the brands analysed: Samsung and LG. Specifically, the research showed that Samsung TVs sent this information every minute, while LG devices did so every 15 seconds. "This gives us an idea of the intensity of the monitoring and shows that smart TV platforms collect large volumes of data on users, regardless of how they consume content—whether through traditional TV viewing or devices connected via HDMI, like laptops or gaming consoles," Callejo emphasises.

To test the ability of TVs to block ACR tracking, the research team experimented with various privacy settings on smart TVs. The results demonstrated that, while users can voluntarily block the transmission of this data to servers, the default setting is for TVs to perform ACR. "The problem is that not all users are aware of this," adds Callejo, who considers this lack of transparency in initial settings concerning. "Moreover, many users don’t know how to change the settings, meaning these devices function by default as tracking mechanisms for their activity."

This research opens up new avenues for studying the tracking capabilities of cloud-connected devices that communicate with each other (commonly known as the Internet of Things, or IoT). It also suggests that manufacturers and regulators must urgently address the challenges that these new devices will present in the near future.

Bibliographic reference: Anselmi, G., Vekaria, Y., D'Souza, A., Callejo, P., Mandalari, Am., Shafiq, Z. (2024). Watching TV with the Second-Party: A First Look at Automatic Content Recognition Tracking in Smart TVs. In Proceedings of the 2024 ACM on Internet Measurement Conference (IMC '24). Association for Computing Machinery, New York, NY, USA, 622–634. https://doi.org/10.1145/3646547.3689013  

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