From Wired:
“For most people who spend a lot of time online, impulsively typing queries into a search engine has become second nature.
Got a nasty infection in an embarrassing spot? Look up a treatment on your favorite search site. Obsessing about an ex? Try Googling his or her name. Chances are the queries will unearth some enlightening information.
But while search engines are quite upfront about sharing their knowledge on topics you enter in the query box, it’s not so clear what they know about you. As operators of the most popular search engines roll out more services that require user registration, industry observers and privacy advocates say it’s become more feasible to associate a particular query with an individual.”