Anonymous Contrubutions
By Lincoln D. Stein
End users are finally learning what Webmasters have known for years -- that surfing the Web is not at all the anonymous activity it seems to be. Every site the user visits, every link she clicks, the contents of every fill-out form she submits, every image she looks at, every message she posts to a newsgroup, is meticulously recorded, collated, and archived on some server, somewhere. Web marketers are eager to purchase this data because it gives an intimate look at the tastes and preferences of a demographic group with disposable income at hand, and many Web sites have no reluctance to sell it. Some banner-advertisement agencies even make it easy to collect this data by providing member sites with data collection and collation services.
Browsers provide many kinds of information about their users. The most fundamental is the IP address and host name of the browser host. The host name can be used to determine what part of the world the user lives in and what company she works for (if she browses from the office), and sometimes gives enough information to learn the user's name. For example, at my previous job, all personal computers were named after the offices in which they were located. With the aid of the university telephone directory (or a helpful receptionist), anyone could track the host name mac_k531.wi.mit.edu back to me.
Browsers give out much more information than just the host name, however. The HTTP-request header includes "user agent" information to identify the browser software, operating system, and hardware architecture the user is running.
