Avoiding unwanted cookies is easy enough, but preserving privacy could mean the end of free access to the Web

Not so long ago, I thought I would take a look at the cookies I had amassed over the last few months. These days, as just about everyone knows, cookies — small files of code that one computer sends to another — are being used as ID tags to monitor what people do on the Web. I found my cookies with a nifty search program called Retrieve-It, which I got at a California computer store; it has a "peek" feature that converts the code to readable English. I had about 30 cookies, including some from Amazon, CNN.com and MSN.com. DoubleClick, an online ad agency, was fourth on the list.

The company has been in the hot seat lately for its intent to monitor what you do online. It didn't take Net ad agencies long to realize that by tracking a person through his cookie's ID number, they could gradually assemble a profile of his interests, even if they didn't know his name and address. Last November, DoubleClick went further by buying Abacus Direct, a company that profiles 88 million households that use snail mail to buy merchandise from catalogues. The merger promised a wholesale linkup of Abacus's addresses and phone numbers with the ID numbers on Internet cookies — once you've been tagged with a cookie a lot of other people are going to be aware of who you are and where you've been. In the furor that followed, DoubleClick put its strategy on hold pending a review by the Federal Trade Commission and several states.

When I called DoubleClick to get their take on cookies, I suggested that cookies might actually be a helpful antidote to info-glut on the Web. Jennifer Blum, DoubleClick's spokesperson, agreed: "The system not only picks ads that are more likely to be interesting, but after you've seen the same ad four or five times, it alerts us and we change it for a new ad." But when I suggested that I come over to have a DoubleClick engineer explain how cookies really work, Blum backed off. "We'll pass on that one," she said. "Take a look at our privacy website. It will tell you everything you need to know." Although the website skips over the nasty stuff, it does volunteer a clunky method of opting out that requires accepting a permanent cookie with a null ID number.

Since the ID is not unique, and hence not trackable, you still get DoubleClick's ads, only now they repeat themselves ad infinitum. A better solution is a "switchable cookie" offered free by Luckman Interactive. Luckman's cookie "anonymizer" renders your cookie file invisible to the rest of the Web. When you want to use a cookie for a specific site, you can switch the cookies back on.

I wondered what Lou Montulli, who invented the Web cookie for Netscape in 1994 to enable online shopping baskets, thought about all this. Before then, there was no way of figuring out what specific users did at websites, much less remembering what a customer ordered. Has the cookie gone too far? Montulli doesn't see any great danger, but he admits that there have been some developments that were not in the original plan, such as stealth cookies hidden by third parties on Web pages (you visit a page and get tagged by cookies from sites you never visited) or security holes (Internet Explorer has one) that allow third parties to see your cookies. When I asked how he felt about DoubleClick, Montulli said, "It's right at the edge of my comfort zone. It seems like they were using it in good faith, but they have the potential to do more."

But how much more? Most companies could care less about the data they have on specific individuals. It's the topography of contemporary culture they're really after. The reason for compiling massive databases is "data mining," a process that involves unleashing supercomputers on vast quantities of data to spot consumer trends that might otherwise go unnoticed. These insights can give a corporation an enormous leap over the competition. Or worse, we'll get smothered in a tsunami of ads, promotional material and distracting enticements designed to play to our greatest weaknesses as revealed by our cookie crumbs.

The alternative, on the other hand, could well mean an end to the free Internet lunch. Says DoubleClick's Blum: "The only reason the Web is free is that advertisers are footing the bill. If there is no return on their investment, they're not going to advertise anymore, and that means that websites will have to start charging for their content." If the choice sounds familiar, it should. It's the same one that turned network television into the wasteland it is today.