The source explains that tracking on the web has moved beyond traditional cookies to a technique called device fingerprinting. When a user visits a website, the browser sends a request that reveals basic information such as the browser type, language, operating system, and IP address. The website then returns code that runs in the browser, allowing it to measure characteristics of the user’s device without prompting for permission. These measurements include GPU behavior and vendor, CPU behavior, vendor and thread count, memory size, display resolution, pixel ratio, refresh rate, audio processing capabilities, and device model. On the software side, the script can detect installed fonts, browser extensions, and various system settings.
Because many of these traits are stable across sessions, combining them yields an identifier that is unique enough to distinguish individuals within a typical sample. The source notes that a fingerprint does not need to be globally unique; it only needs to be unique enough to separate users in the data set being analyzed. For example, a combination of inferred ZIP code from IP address, self‑reported birth date, and sex can already identify over 60 % of Americans, and adding further hardware or software traits reduces the pool of possible matches dramatically.
The source contrasts fingerprinting with the earlier debate over third‑party cookies, noting that regulations such as the EU’s consent banners were introduced amid concerns about cookie‑based tracking. It mentions that one major tech company, which holds roughly two‑thirds of the browser market, initially pledged to eliminate cookies and replace them with a privacy‑first alternative, but later shifted to promoting fingerprinting through its advertising products while offering limited protections such as IP‑address masking only in certain incognito scenarios.
Privacy‑focused browsers attempt to counteract fingerprinting. Brave adds random noise—a technique referred to as “farbling”—to make the fingerprint inconsistent from one visit to the next. Tor and the Mullvad Browser take the opposite approach, striving to make all users appear identical by standardizing the exposed device and browser characteristics, thereby preventing any reliable differentiation.
The source concludes by framing the collected data not as a tool for personalized advertising but as a commodity that can be sold to the highest bidder, whether commercial advertisers, governments, or other interested parties. It warns that the resulting profile can reveal more about an individual than they might know themselves, raising questions about autonomy and the extent of surveillance in the digital economy.