Meta injecting code into websites visited by its users to track them, research says

Meta, the owner of Facebook and Instagram, has been rewriting websites its users visit, letting the company follow them across the web after they click links in its apps, according to new research from an ex-Google engineer.

Krause discovered the code injection by building a tool that could list all the extra commands added to a website by the browser. For normal browsers, and most apps, the tool detects no changes, but for Facebook and Instagram it finds up to 18 lines of code added by the app. Those lines of code appear to scan for a particular cross-platform tracking kit and, if not installed, instead call the Meta Pixel, a tracking tool that allows the company to follow a user around the web and build an accurate profile of their interests.