Britain’s data protection regulator, the Information Commissioner’s Office (ICO), has criticized Google for allowing advertisers to track users through digital “fingerprints,” a technique that could undermine consumer privacy. The ICO described the practice as “irresponsible,” warning that it would make it difficult for even privacy-conscious users to block tracking, as fingerprinting is harder to detect than traditional cookies.

Fingerprinting collects signals from a device’s hardware and software to uniquely identify users, functioning as an advanced form of cookies. Unlike cookies, users cannot easily clear or consent to fingerprinting, which reduces their control over how their data is collected, the ICO stated.

Google announced this week that, starting in mid-February, advertisers will be able to use fingerprinting to reach audiences on smart TVs, streaming services, and connected gaming consoles. The company emphasized advancements in technology that enhance user privacy in this space. However, Google’s shift contradicts its 2019 stance, where it acknowledged that fingerprinting undermines user choice.

Stephen Almond, ICO’s executive director for regulatory risk, warned businesses that fingerprinting must be deployed transparently and in compliance with data protection laws. The ICO may take action if companies fail to meet these standards.

Google responded, stating that it will engage in further discussions with the ICO and emphasized its commitment to privacy-enhancing technologies, allowing users to choose whether to receive personalized ads.