There was quite a kerfuffle earlier this year when the news broke about the surveillance tactics being employed by the National Security Agency (NSA). Many people were concerned that the government was listening in on their phone calls and tracking their movements. Several years ago (pre-September 11), I worked at NSA, so I heard this news with some amount of mild amusement. I wasn’t the least bit concerned about being targeted by the massive computing power of NSA; they have their hands full chasing people that need chasing.

Instead, my reaction was based on something more practical. If you think your privacy is being challenged by the government, then you may not be paying close enough attention to the world of marketing.

With computing power ever-increasing, there’s a new trend emerging called “Big Data” that is all the rage. It can mean different things to different people, but for ease of use and understanding, think of big data like this: Because computing power has become so advanced and data storage has become so cheap, we have the capability to store, retrieve, and analyze millions of data points fairly quickly. These data points can be almost anything, from income to interests to your web browsing history. Marketers have realized the value of this information is in predictive analytics. By using what they know about you and comparing to other people like you, they can make predictions of how you’ll behave in the future.

This is pretty heady stuff, so here’s an example to help bring it home. Every time you shop at Target, they collect information about all of your purchases and put it into a bucket that is identified with your unique Guest ID. They also couple this purchase history with any demographic information they can gather, either directly from you or from other sources. So with this data, they were able to run specific tests to determine the purchasing habits of women just before they put themselves on the baby registry. Using this purchase information, Target is able to create a “pregnancy prediction” score. They can also estimate a due date within a small window, allowing them to send very specific coupons timed to specific stages of the pregnancy.

Ultimately, this led to an incident in Minneapolis where a father went to local Target complaining about a flier his high-school-age daughter received in the mail. It contained coupons for baby clothes, cribs, and other maternity-related items. Turns out that Target knew his daughter was pregnant before he did. (There’s a great NY Times article about this called “How Companies Learn Your Secrets“)

So the NSA certainly has some stunning capabilities, but if you’re going to be concerned about complete strangers learning your secrets, you’d be better served to start with marketers and big data. And the place to start is Acxiom. Axciom is one of several companies built around supplying this type of information to businesses to help them better target the offers you receive. From an altruistic point of view, this helps you find better information and offers for products you are likely to purchase anyway. From a Big Brother point of view, they may know way more than you’d be comfortable with.

Anticipating the potential backlash that might arise from a grass roots effort, Acxiom has made its entire database of information available online. Start at About the Data. You can log in to the site, provide some basic information to show your identity, and see everything they “know” about you.

The dataset is culled from a variety of sources, including credit reports, public records, purchase history, and probably any survey you completed showing your various interests. In my case, most of the information was correct or pretty close. (They had the right number of kids but the wrong ages, for instance.)

The depth and breadth of information shown collected can be a bit overwhelming. The site does a nice job of breaking it into bite-sized pieces, but they’re still pretty big bites. Under Household Purchase Data, for example, there were more than 50 categories of information displayed. This is just one of six different categories. The others are Characteristic Data, Home Data, Household Vehicle Data, Household Economic Data, and Household Interests Data.

The cool part about all of this (once you’re over the creep factor), is that you can correct or delete information and designate whether you want certain types to be used for marketing purposes.

You can also opt out completely if you choose. But understand: the opt out is a bit of a Trojan Horse. The site describes the process like this: “This will not reduce the number of ads and offers you receive, it just means that some of them may be less relevant to you.” Which is worded smartly enough to make anyone hesitate before doing it. Which is also precisely the point. (You see what I mean about marketers? Much scarier than the government.)