Don't you hate it when you search for something, and then ads related to your searches follow you around for days? By now it's common knowledge, but Google and other search engines are tracking and creating a detailed profile about you based on your searches.
If that wasn't bad enough, the privacy policies of the most popular search providers state that your search history may be associated with any account or other information they may have about you, such as your email address, first and last name, scans of your face from your photos, your location, and other sensitive details. Your search history is then tied to this profile to target you for a period of several months to years.