These little requests for information often go unnoticed. Combined with your credit information, education history, medical records, census info, etc., the data is used to create eerily accurate profiles. These profiles are then made available to third parties that resell the information to marketers and advertisers, often without your knowledge or consent. In the physical world, we tend to act differently depending on the situation we're in, who we're with, who's watching, etc. For example, Susan might act one way in a conversation with her friends, but completely different in an interview with a potential employer.
Many people use the Internet for a number of different activities.
These different activities are currently all related back to a single digital identity. Everything Susan says or does online is automatically tied in to her actual identity. Details about what individuals do online are extremely valuable to businesses seeking to target customers. Sophisticated technology enables companies to track and analyze your browsing habits, including not only what sites you visit, but the path you take through the site as well. Your profile is often bought and sold without your knowledge or consent, resulting in a barrage of junk mail in your inbox.