The Next Online Privacy Battle: Powerful Supercookies

Since the early days of the Internet, major companies and even minor ones have been watching you. You can't really blame them; they need to do it as it helps to sell targeted advertisements and monetize the content you're oftentimes getting for free. They watch what sites you come in from, how long you stay on their site and what pages you visit during your stay. They monitor your scroll depth on individual posts (how far into the content you make it before fleeing to another page) and read any comments you might leave. Much of this is done with the help of HTTP cookies, a little packet of information that saves user preferences and anything else that can be written as text.

Like Facebook, cookies have drawn some serious ire from privacy proponents. But, like Facebook, there are some actions that those concerned enough can take to protect themselves. You can log in to your account on the social network and change preferences to keep the most private of information out of the hands of those that search for you. And you can tweak the settings, which, in the case of Facebook almost always default to be the most open and transparent, so that third-party applications are unable to scrape your data. With cookies, your control is more absolute: You can just delete them. Every browser makes it pretty simple, no more than a few clicks.

But now, according to the Wall Street Journal, control is slipping away from the user. Big websites like Hulu and MSN are tracking visitors with supercookies, "which are capable of re-creating users' profiles after people deleted regular cookies," the paper reports.

The new tracking tool was discovered by researchers at Stanford University and the University of California at Berkeley. When the joint team brought their findings to the attention of the companies found to be using supercookies, many, like Microsoft, MSN's parent company, claimed to be unaware of the technique and said that it is "inconsistent with our intent and our policy."

One of the supercookies that the researchers found on, a Time Warner-owned service that provides movie news, reviews and showtimes, was capable of looking back at Web-browsing history. The cookie would dig around to see if its newest victims had visited any of more than 1,500 websites in the past, including, the Journal notes, those dealing with menopause, credit repair, fertility problems, and more. Presumably, the cookie was looking to see what sorts of products those it had infected might be interested in buying. It could then provide that information to an online advertising network, which would turn it around and serve up an ad for Clomid.