Your privacy on the Web, Part 1: How some sites track your every move

Just because you're well behaved doesn't mean everyone else is.

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Al Fasoldt's reviews and commentaries, continuously available online since 1983

Your privacy on the Web: How some sites track your every move

Nov. 8,, 2000

By Al Fasoldt
Copyright ©2000, Al Fasoldt
Copyright ©2000, The Syracuse Newspapers

   You see advertisements on the Web all the time. Most of them are simply that -- commercial messages from advertisers.
   But you probably don't know that some of the ads your Web browser picks up aren't so benign. Some are insidious attempts to violate your privacy. This would be bad enough if the ads that try to spy on you were visible. But you'd never spot them without help. They're invisible. Your Web browser can't show them to you and you never know these ads are there.
   The idea that someone would actually plant invisible spyware on your screen shows how low we've sunk as a networked society. I'll explain how that works this week. Next week, I'll suggest ways to take back your privacy.
   The problem is not just advertising. In fact, you probably could argue that the problem isn't advertising at all.
   The problem is whether advertisers (and companies that advertisers hire to do research) should get away with violating your privacy. Here's an example that has nothing to do with computers or the Internet. I'm making it up, so please don't think that what I'm going to tell you actually happens, although there's no reason to think it WON'T happen some day.
   Here's my example. Suppose some of the billboards you see along side the road had tiny video cameras hidden in the signs -- peering out through the center of the letter "O" in the middle of an advertising message, maybe. And let's say those video cameras were hooked up to video recorders that ran day and night. The cameras were trained on the faces of the drivers of all the cars that went past each billboard. Anyone who studied the tapes could tell which drivers looked at the billboards and which didn't.
   And since the videos would also show the license plates of each car, anybody who had the tapes could find out who owned each car (and therefore who was most likely to be driving). You don't need any more of an explanation to know what I am telling you. They'd know who was looking at the ad and who wasn't. They could send you advertising in the mail if they thought you were ignoring certain billboards.
   It could get a lot worse, as you can imagine. The federal government might want to know how effective its publicity campaigns are. Maybe it's got billboards that remind us to vote. If you drive by without looking at the message, are you still a good citizen? Should you be required to prove that you are?
   This sounds like nonsense. But let's see what's actually happening on the Web.
   Advertisers and ad-tracking companies often plant very tiny images on Web pages. These images are so small -- a single pixel (one dot on the screen) in size -- that they load instantly. Your browser hardly slows down even if there are many of them. These little images, called GIFs, are transparent, so even if you could see a single-pixel image you wouldn't know it was there.
   These tiny GIF images are called Web bugs. They're bad news.
   Web browsers are polite. They ask the computer on the other end of the connection for a file -- for a Web page, for example, or for an image. The computer on the other side, called the server, keeps a record of what happens. It knows, for example, that a Web browser from, say, "xyz.internet.provider.com" logged on at 9:35 on Nov. 6 and downloaded an image file. That image file could be a tiny, transparent GIF file.
   You might not know that Web servers sometimes can pick up your e-mail address by a little trickery. The folks who are tracking you would then know that Jane Doe viewed a certain page at 9:35 on Nov. 6 (because a Web browser operated by someone who has a "janedoe@xyz.internet.provider.com" e-mail address asked the Web server to send it a specific transparent GIF file at that time).
   Does this matter? So what if someone keeps track of what you're doing on the Web. You're not doing anything wrong, so why worry about it?
   No, you're not doing anything wrong, and that's the point. The people who are tracking you are doing something wrong.
   That's why you should be concerned. Just because you're well behaved doesn't mean everyone else is. You'd probably be surprised to discover that some people would love to know what you were doing at a certain time on a certain day for all sorts of reasons -- to prove that you weren't supervising little Johnny when he got into trouble with the music teacher, maybe, or to have evidence that you were looking at a site run by your employer's competitor, that kind of thing. The possibilities are endless.
   That's why you need to preserve your privacy. Next week I'll describe some of your choices.