Bookmark: "TeamViewer installs suspicious font only useful for web fingerprinting"

Sebastian Greger


Browser manufacturers are in a constant battle of finding ways to protect users from being fingerprinted by websites they use. I just recently was very surprised to visit an online store (with emptied local storage, all cookies deleted, and trackers efficiently blocked) which instantly recommended me to “Continue where I last stopped” and showing me the one product I had assessed a few days earlier. Needless to say I won’t ever buy anything from that company.

This case of a software manufacturer using a custom font to fingerprint users is another appalling example of such unethical conduct: On installing their software, they install a custom font on the user’s machine which is then – every junior-level web developer knows how – easy to check for its existence. Even if the company claims to do this in order to prevent fraud, this still is a massive intrusion into users’ privacy and puts the conduct of that company in a very bad light (they apparently have since changed their practice after the public backlash).

As a side note: anybody doing this kind of intrusive sniffing in the EU hopefully is aware that it is very likely a violation of the ePrivacy directive and its national implementations: assessing “information stored on a user’s device” (which in my book is very much the case when looking for installed fonts) always requires explicit consent.

I'm Sebastian, Sociologist and Interaction Designer. This journal is mostly about bringing toge­ther social science and design for inclusive, privacy-focused, and sustainable "human-first" digital strategies. I also tend to a "digital garden" with carefully curated resources.

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