By Joanna Glasner
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.
"You should think about what you put in that search box, because it may not be as anonymous as you think," said Danny Sullivan, editor of SearchEngineWatch.com.
It has long been standard practice, Sullivan noted, for search sites to employ cookies, which track activity on a computer's internet browser. But cookies don't identify a person by name. If two people access a site on the same browser, the cookie wouldn't distinguish between them.
However, when people provide personal information to register for services offered by search engine companies, such as free e-mail accounts, news alerts or personalized homepages, they're no longer anonymous.