Why do people report on themselves?

Not long after I started using Twitter, I started to wonder: Why?

Imagine the familiar movie scenario where a detective is desperate to track and find a suspect, or where a detective is hired by a suspicious spouse to trail their errant husband or wife. Or an alternate scenario from the Cold War, where the secret police manipulate ordinary citizens to inform on one another (cf. the film The Lives of Others, pictured at left). Or the horrible situation of a controlling husband who wants to know where his wife is at every minute of the day. In those situations, one person wants to track another; the person who is tracked would rather not be tracked and sometimes would do anything to avoid it.

Now consider yourself, or any ordinary bourgeois, and how much you are tracked on a daily (and sometimes minute-to-minute) basis. Credit card companies and credit reporting firms register every purchase you make with something other than cash. Airlines, grocery stores and other businesses with rewards programs know where you've traveled and what you've bought. The phone company knows, within a few hundred feet, where you made that cell phone call from, and if you have GPS enabled, they know within a few meters.

And so on. Any modern consumer knows all this, so there's no need to go into it at length -- though the Wired story Gone Forever: What does it take to really disappear? is somewhat of an eyeopener, in that it communicates the ease with which some modern-day gumshoes, such as private detectives working for bail bondsmen or insurance companies, can locate you through the databases compiled by airlines, Amazon, Visa and others.

You may or may not feel comfortable with all that tracking and archiving of data about you, but there's not much you can do about it. After all, you "agreed" to it when you signed up for whatever credit card, rewards program, cell phone, etc. etc. you use. Just check your "End User License Agreement."

If this makes you feel just a little bit creeped out, then I would ask you: Why do you have a Facebook page? Why are you on Twitter? Why do you post your name, address, preferences and picture online on any number of sites, from Amazon to Yelp? In my novel How They Scored, I put it this way: Why would you even need an East German-style secret police these days when people are putting so much effort into reporting on themselves, compiling their own dossiers? (We call them online "profiles.")

There's no need to be needlessly paranoid about this. No one (unless he or she is actively stalking you) has hired a private detective to compile a report on the details of your quotidian doings. But they could. Because your life's an open book.

I'm aware of all this and I still tweet what I'm doing, what I just ate, where I am. I still blog about books I read or music I listened to (facts which, if they were in the records of the public library, would require a court order for anyone to access, but I give them away for free). I still have my picture online in a dozen places, along with the neighborhood I live in, and so on.

But I still rebel in small ways. For example, I don't have a Safeway card, but I still take partial advantage of their program. How? I thought to myself, probably most people in the neighborhood of this store have Safeway cards. All I have to do is type in the local telephone exchange and four random numbers. For the Safeway on 29th and Mission, in my neighborhood of San Francisco, that's 415-824-xxxx. And it almost always works. I get my TV dinners 4 for $10 and whoever actually owns the account gets some points toward the purchase of ... whatever Safeway gives. That's my big protest.