Instagram injects Meta’s Meta Pixel JavaScript tracking code into every website that you open. It’s a library designed for website developers to track visitors on their site.

According to the lawsuits, Meta has been injecting javascript tracking code into websites that users visit via the in-app browsers in Facebook and Instagram for iOS, but without user permission.

While TikTok said the code’s only used for debugging, researchers also found Meta products Facebook and Instagram can track users’ in-app browser.

Chrome extensions with 1.4M installs covertly track visits and inject code If you've installed any of these extensions, manually remove them stat.