Special note.. the page includes a html code that will read your LJ cookie if you allow cookies to be read by sites other then the original, and display your name in it (to you only). This has alarmed some of the readers of the essay, which I believe was the whole point. No matter how anonymous the internet may feel at times, it really isn't nearly as easy to remain anonymous as many people would like to believe it is. More to the point, a lot of people leave many system defaults as is, and most common software defaults to a very insecure state. Cookies for instance have many uses, not all of which are benign.
Edit: Oh, apparently it's not related to the cookie, but to the LJ referrer ID.