Pew – Aaron Smith – What Is a Privacy Policy: Research by “Joseph Turow [who studies digital marketing and privacy issues at the University of Pennsylvania’s Annenberg School for Communication] …also suggests that ordinary users don’t fully understand the scope of the data that is being collected on them — or how small amounts of data can be used to create a much more detailed portrait when matched with information from third-party sites that collect and share various types of customer information with each other. “The general sense among marketers is that people understand that their data is being used, but we’ve found in our research that people don’t truly understand how data mining works. They may realize that one or two pieces of their information are being given out; what they don’t realize is that those one or two data points can be linked with other sources to uncover information they would have never given out in the first place.”