On the Web, Children Face Intensive Tracking
theodp writes "In the latest installment of their online privacy investigation, the Wall Street Journal reports that children face intensive tracking on the web, finding that popular children's websites install more tracking technologies on personal computers than do the top websites aimed at adults. In an analysis of 50 sites popular with US teens and children, the WSJ found that Google — whose execs recently lectured parents on online child safety — placed the most tracking files overall."
You could tell an awfull lot about a person or family by knowing everything they visit online.
A single site operator can't tell all sites you visit. Your ISP can, and if they are sharing that data it's a little scary.
Google knows everything you do.