06/19/2013 06:52 pm ET Updated Aug 19, 2013

Eeeek! I've Been Snooped!

The idea that the United States government might be spying on some of our personal communication is a little creepy. If I phone a friend in Baghdad, Kabul or Moscow, or even London or Paris, there's apparently a chance that a record of my call could wind up in a National Security Agency electronic file. Or if I email my cousin in South Dakota to exchange recipes for home-made cherry bombs or bottle rockets to celebrate July 4th, there could be a record of our discussion at NSA Headquarters.

Recent revelations about government snooping have generated another firestorm of anger and suspicion. Folks from both ends of the political spectrum are outraged that the U.S. Government could be keeping an eye -- or an ear -- on communication in and out of the country. But, at the same time, a sizable majority of citizens are okay with the national security agency keeping data on overseas telephone calls or emails with certain words or phrases in them. Maybe they're not delighted at the prospect, but they're feeling a little less secure in a post-Sept. 11th world and realize that individual privacy must be balanced to some degree with the needs of our national security.

However, what's ironic about an overreaction to the NSA revelations is that Americans are "spied on" every day. Intensely personal data about all of us are captured and recorded and sold, and it doesn't require an overseas phone call or email. All it takes is a trip to the grocery store or drug store or a restaurant or a department store, buying a book from Amazon or a new bathing suit from Land's End or just browsing the Internet. Nearly everything you buy, every meal you eat out, every website you visit or every online ad you click on is recorded.

The process is called microtargeting. We leave a trail of information about ourselves from credit cards, magazine subscriptions, memberships in organizations, charitable or political contributions, buying a car, bank and home loan data, tax records -- even grocery store and drug store discount cards. Surfing the web leaves a trail of browser history that allows insight into our personal interests. Do you read the New York Times or watch Fox News? Do you have children? Do you shop in high-end boutiques or search for deals on Craigslist? Have you contributed to the Sierra Club or Habitat for Humanity or Club for Growth?

The marketing industry uses this data to build a profile so advertising can be precisely targeted to you. Google, Facebook, Apple and thousands of other companies want to profile us to help advertisers craft more effective ads. The companies paying for this research want to know what, where and how you buy. And in addition to knowing what you've purchased, they know your income, where you live, what kind of car you drive and your credit history.

Beyond its role in sharpening and individualizing consumer advertising, microtargeting has become an essential tool in political campaigns. Consumer information can be overlaid on your voting history, allowing candidates, political parties and interest groups to target a message that's pretty well guaranteed to get your attention.

Political organizations and strategy firms gather or buy such data. They match it to publicly available voter rolls to generate detailed information about how often a potential voter has actually voted, in addition to what they read and where they shop. This helps determine how they might vote and how best to reach them with a political message.

Does all this mean we shouldn't be a little worried that the National Security Agency could be gathering email or tracking international phone calls? Hardly. Anytime our government feels the need to infringe even a little bit on personal privacy, we ought to be concerned. Even if it's done to help keep us safe from terrorism, a little concern and skepticism are absolutely appropriate. But unless you're in the espionage business or a secret terrorist, you probably have more to worry about from using your credit card at the mall, making fun of the boss in an office email or posting your private thoughts on Facebook.