AOL's publication of the search histories of more than 650,000 of its users should reinforce an important point: What you type in online may not be as private as you think. Search engines place a multibillion-dollar infrastructure at the hands of any random user who stops by their Web site. The price you pay, however, is that the company may hold on to your search queries--which can provide a glimpse into your life--forever. To offer some suggestions about preserving your privacy while using search engines, CNET News.com has prepared the following list of frequently asked questions.

Q: Why did AOL publish those search histories?

A research arm of AOL published the data in hopes the information would help other scientists and statisticians learn more about how people use the Internet. AOL apologized for this on Monday, saying the release had not been properly vetted.