One big security topic, widely discussed today, revolves around the protection of our privacy as we surf the Web. We've long known and understood that e-commerce websites we visit keep track of information about our shopping preferences, habits, even what products we've viewed online. What most don't know is that search engines are also keeping track of what we are looking for online. So, just what is the Google tracking code.USA Today has a lengthy article today discussing web tracking ("Web tracking has become a privacy time bomb"). The article covers many aspects of this issue, commonly referred to as shadowing. As you shop, research, job hunt and socialize online, many of these sites are compiling your information and selling it in online brokerages to advertisers.

Before you get up in arms, though, realize that the purpose of gathering this information is not criminal or even sordid. The advertising networks, such as Google, Doubleclick, Yahoo! – any site which sells and displays advertising on other sites — has one primary goal: to improve advertising performance by displaying ads they think are most appealing to you.

To do this, the networks have to store a cookie in your browser so that as you go from one website to another, this information can be used to identify you to the networks. The cookie does not store any personal or confidential information; it's simply an identifier, like and ID number.However, what you disclose on websites that compile and share information, can include information you may not want disclosed. It's not that sites purposely disclose confidential information – some sites are inadvertently disclosing information.Profile information of Facebook users has been gathered through third-party Facebook apps and sold to marketers. And in other cases, the use of your Facebook profile information is being used by Facebook to help advertisers target users. That's one reason I keep seeing ads for University of Texas Longhorns apparel, since I list UT as my Alma Mater.

But the use of your information goes further. When we were in the market to buy a car last year, two of the sites I visited were Buick and Hyundai (we bought a Hyundai). For weeks thereafter, wherever I went on the Internet that displayed ads from the Google advertising network, I saw ads for Buick and Hyundai. By visiting their websites, my cookie was tied to my shadow profile which, because Buick and Hyundai shared my visit information with a central tracking database, caused the advertising networks to determine that ads for Buick and Hyundai would be more attractive to me.

The Impact to Your Search

As you use Google, Bing or Yahoo! (and others probably do this, as well), the search engines are analyzing not only your search terms, but which of the results you click on. Again, it's not to be sneaky, but their effort to show you results that they feel you'll find more relevant to your needs. This impacts what we, as web engineers do, because even though we might get high rankings for a clients' website for one search, another visitor might see an entirely different ranking based on what Google, for example, considers to be more or less relevant results.

I know, this all sounds geeky and outside of your control. Not for long, though. There are numerous discussions going on in Congress and elsewhere to consider regulating how your profile data is collected and used.Plus, you also have some level of control yourself.

Changing the Rules: the Google Tracking Code

A few weeks ago, in doing research for an e-commerce site we engineered to sell pilot and aviation supplies, I visited several aviation-related sites, including plane manufacturers. What I found out – and I'll show you how to do the same for you – was that Google recorded the assumption that I had an interest in recreational aviation. Any advertiser who wanted to, could use that fact to target ads selling planes and related products on websites I visit.So, how do you know what Google is analyzing when you surf? In your browser go to http://www.google.com/ads/preferences/view.

You should see a list of categories Google has been tracking with your searches. These are the categories Google feels you are most interested in. For me, the list was pretty much on the mark, although given the scope of my work, my category interests are all over the map.It also listed demographic information: my age bracket and gender. It had the gender correct, but the age bracket was wrong.Fortunately, however, you can Opt-Out of allowing Google to do this tracking. It won't keep others from tracking your online behavior; the depth of shadowing is quite extensive.But before you click that Opt-Out button, you might simply want to remove categories you're really not interested in, as well as any incorrect demographic information. It doesn't hurt that Google is trying to help you find what you want. That's the intent of the search engines: to show you the most relevant results for your search.

Me? I'm staying in. I'm correcting the categories (although I like the fact Google thinks I'm younger than I really am), but I do want search results that are more relevant to my interests.What we all need to do, though, is to keep a close eye on what transpires over the coming months regarding the collaboration of various information-gathering databases who use this information in ways we may not want.