Cookies - How The NSA Is Using Them To Track Tor Users: Let's suppose that there is an online shopping website, owned, or controlled by the NSA. When a normal user will open that website from his/her real I.P. address, the website creates a cookie on the user's browser and stores the real I.P. address and other personal information about the user. When the same user will again visit the same NSA owned website, enabling Tor this time on the same browser - the website will read the last stored cookies from the browser, which includes the user's real I.P. address, and other personal Information. Furthermore, the website just needs to maintain a database of real I.P. addresses against the Tor Proxy enabled fake I.P. addresses to track anonymous users. The more popular the site is, the more users can be tracked easily. Documents show that the NSA is using online advertisements, i.e. Google Ads to make their tracking sites popular on the internet.