As "do not track" has taken center stage in debates about the Internet and personal privacy, many Web users remain unaware of exactly what tracking is and what it does -- or that they're even being tracked as they surf the Internet.

Tracking has been defined by the Center for Democracy and Technology as "the collection and correlation of data about the Internet activities of a particular user, computer or device over time and across non-commonly branded Web sites, for any purpose other than fraud prevention or compliance with law enforcement requests."

In simpler terms, it's what happens when you browse Web site A in the morning searching for a recipe for barbecued short ribs then when browsing Web site B that afternoon you are suddenly presented with an ad urging you to buy a stainless steel, propane-powered backyard barbecue "for a low, low price."

Coincidence? Hardly. You've been tracked.

Web site A gathered information about your visit and your search, and then placed a small file known as a "cookie" on your browser. Meanwhile, it sold that "profile" information about you and others making the same sort of search to a third-party tracker.

Web site B, which also works with the same tracker, picks up that profile from the cookie, takes note of the connections, and presents you with the ad for the barbecue, from which it makes money from the advertiser.

Although seemingly harmless and even beneficial -- if you are, in fact, thinking about buying a barbecue -- there is a dark side to tracking, as third party trackers collecting data can correlate that with other databases containing geolocation, financial and medical information.

Eventually, the tracker can build a profile predicting your age, gender, zip code, income, marital status, parenthood, home ownership and other identifying parameters.

Through tracking, you are now a valuable "target" to advertisers and marketers.

In response to complaints from privacy advocates, legislators and government agencies are beginning to look at the issue of Internet tracking.

Last week, the Federal Trade Commission, issued a report laying out proposals to require businesses to give consumers more control over the collection and use of personal data.

And last month, the White House released a Consumer Privacy Bill of Rights, which President Obama said would give consumers "clear guidance on what they should expect from those who handle their personal information, and set expectations for companies that use personal data."

One immediate result is that makers of the major Web browsers have begun providing or preparing do-not-track capabilities for their software, while third-party browser "add-ons" with the same capability are available.

Security firm AVG has announced a do-not-track feature for Windows that will run as an add-on for Internet Explorer, Mozilla Firefox and Google Chrome browsers that actively seeking out tracking cookies and alerts users if a site is attempting to set a tracking mechanism.

And online privacy company Abine has released a add-on called Do Not Track Plus for Chrome, Firefox, Internet Explorer and Safari designed to block advertising companies and social networks from gathering personal information through online tracking of a user's browsing habits.

Last week Yahoo Inc. announced it would offer its own do-not-track feature on all associated Web sites by this summer.

Mozilla is working on do-not-track feature for its own Firefox browser and in 2011 Microsoft introduced a do-not-track feature for Internet Explorer 9.

So while you may not in fact mind that ad for a new back yard barbecue popping up in your random Web visits and searches, you may soon have the option of deciding if being tracked is worth it -- or not.