[clintonb]

> What's the worst thing that could happen from Google tracking me across the web could?

Discrimination. Public humiliation. You assume Google is only using the data it collects to show ads. What if they sold the data other organizations? What if the data was used to prevent you from getting a job or membership to an organization? What if there was a data breach, and suddenly everyone knew about every site you visited?

Taken to a further extreme, what if the government used this data against you to strip you of certain rights/privileges?

These scenarios may seem extreme, but they are all feasible. You and I may not have anything to hide, but others may, and they are entitled to that privacy.