keep track of and monitor an individual user’s web activity over every website on which these companies inject ads.2 These third-party cookies are used by advertising companies to help create detailed profiles on individuals . . . by recording every communication request by that browser to sites that are participating in the ad network, including all search terms the user has entered. The information is sent to the companies and associated with unique cookies—that is how the tracking takes place. The cookie lets the tracker associate the web activity with a unique person using a unique browser on a device. Once the third-party cookie is placed in the browser, the next time the user goes to a website with the same [d]efendant’s advertisements, a copy of that request can be associated with the unique third-party cookie previously placed. Thus the tracker can track the behavior of the user . . . .3 B. Discovery Cookie Blocking, Circumvention, Deceit, and Individually tailored webpage advertisements are now ubiquitous. But, where cookie-based tracking is concerned, leading web browsers have designed built-in features to prevent the installation of cookies by third-party servers. The 2 Compl. ¶ 45. 3 Compl. ¶ 46. 7