Whether you're searching Bing, Google, Yahoo, or any other the other major search engines, or just a website like Amazon or YouTube, you leave behind a search history that can say a lot about you.
Although you might take to the computer to search online for stuff that you'd never talk about in person, many websites anonymously collect search query data. Interestingly, studies involving this data reveal how people have curiosities that can tell a story about who they really are.
These search results can then be connected demographically to specific locations or other attributes, like age, race, religion, and many others. Websites don't typically know this much about you from the start, but merely conducting several searches can provide clues that build an identity; this is the same concept behind the game 20 Questions.
Understanding how these statistics are collected and used is a constant reminder that your internet browsing isn't private. On the other hand, it can also be interesting to know where everyone's minds are at, and this video provides fairly good insight.