Web Security, Privacy and Commerce, 2nd Edition

Chapter 24. Privacy Policies, Legislation, and P3P

Online businesses know a lot about their customers. An online merchant knows every product that you look at, every product that you put in your "shopping cart" but later take out, and anything that you've ever purchased from them online. Online merchants also know when you shop, if you shop from home or from work, and if they care what your credit rating is. Furthermore, unlike the offline world, an online merchant can correlate your shopping profile with your web browsing habits.

Internet service providers can learn even more about their customers because all information that an Internet user sees must first pass through the provider's computers. ISPs can also determine the web sites that their users frequent and even the individual articles that have been viewed. They can analyze email messages for keywords. By tracking this information, an Internet provider can tell if its users are interested in boats or cars, whether they care about fashion, or even if they are interested in particular medical diseases.