[Reposted from my Red Herring blog, 2005]

Recently BBC World had an article on baby blogs– blogs that parents will keep about their children, the digital equivalent of baby books. Coincidentally, that same day I posted my 500th entry on my blog about my children, which I started soon after getting a digital camera. Like most articles about blogs, its substantive points were mixed up with a measure of alarmism and technical naivete. Some of it was taken up with worries about what pedophiles unmentionable things could do to those cute baby pictures, and fretting over how revealing details about your child's daily routine isn't very smart. (Hello? Ever heard of password protection?)

The article also suggested that baby blogs were invasions of privacy. What if, twenty years from now, the merest acquaintance could read about your child's potty-training exploits, or their first visit to Grandma's house? Wouldn't making those details of your child's life available to people they barely know violate their privacy, and make it harder for them to get dates? (At this point in the article I wanted to pump my arm and shouted "Yessss!" My five year-old daughter is only in nursery school, and already I've guaranteed that she'll spend her college years undistracted by a social life.)

My efforts to archive my children's lives stand in stark contrast to the scanty documentation of my own past. My entire childhood is preserved in just under two hundred pictures, a few letters, and a couple yearbooks: it all fits in a single box. In contrast, I can take two hundred pictures of my daughter at a birthday party. The constantly-falling cost of digital media lower the barriers to recording everyday events, and preserving every last picture and audio file. At my current rate, each of my children are in danger of having me take 50,000 pictures of them by the time they turn 18.

Of course, parenting is one long invasion of privacy, but the idea of baby blogs coming back to haunt their subjects later in life is still an interesting one. Technology promises to take a ritual that had traditionally been a painful but very limited rite of passage– the baby books shown to the fiance, the clever candids shown at the wedding reception– and make it into a full-time affair.

It also shows that the relationship between privacy and technology is really pretty complex. Worries about technology affecting privacy are perfectly reasonable; but worries about specific technologies are often misplaced. To really know what to worry about, you have to think a bit more about what privacy is, and how technology can affect it.

One of the most famous descriptions of privacy is Samuel Warren and Louis Brandeis' dictum that it consists of "the right to be left alone." Most of us still think of privacy as something mainly threatened by intrusive actions, such as government surveillance or aggressive marketers. It's no surprise, then, that when people worry about technology affecting privacy, this is what they usually think of. We usually speak of technology "eroding" privacy– an active verb, but also a subtle one.

This has a couple implications. For one, it suggests that new technologies don't destroy privacy overnight. Video cameras, for example, creep into more and more public places, recording our actions and reducing our anonymity: an airport or corporate headquarters today, tomorrow the local park.

For another, it suggests that these technologies move with the stealth of geological forces. RFID tags in currency or objects would make it easier for our actions and habits to be tracked. What scares many people out about RFID is that the tags can be hidden so easily.

The metaphor of "erosion" also suggests that these technologies can be resisted, through legal restrictions, technical countermeasures, or smart consumer choices. Privacy advocates, most notably CASPIAN, have called for legal limits on the use of RFID tags, and a consumer bill of rights regarding RFID. Others argue that RFID tags aren't quite the Orwellian tools that critics make them out to be. The tags have to be "interrogated" by a reader, sending out a distinctive signal that can be easily detected– and possibly intercepted. Further, the low range of tags means that a police state would require a gigantic number of readers to track its citizens. Dictatorships require more efficient tools.

The RFID example also highlights one other essential aspect of the technology-privacy relationship: the information generated by technologies isnt' usually the problem, it's who controls it. While writing this article, I wanted to quote an article I read a few months ago that discussed four forms of privacy. I often find I want a Google for all the stuff I read, so I can answer those "where did I read about…" questions. I'd be mad if any search engine kept track of everything I read, but I'd love to have that functionality for myself.

Indeed, no technology is inherently a threat to privacy; the threat comes in how the technology is used, and who controls it. The "<a href="http://Blogger.iftf.org/Future/000178.html">personal server</a>," a personal device that could carry all of a user's digital data and record everything they do, would be immensely useful to busy people in free societies. Totalitarian states would also love it: it would be My Big Brother, always watching, always listening. It's one thing for me to keep a diary, quite another for a government agency to keep a file on me.

So where do baby blogs fit on that spectrum?

We've seen that it's possible for technologies to "invade" or "erode" privacy, but also for them to be designed and used in ways that limit their impact on privacy. But baby blogs don't follow the active model of privacy invasion, for they affect another kind of privacy: privacy from one's past.

Simply put, the notion of privacy from one's past is that– with rare exceptions, like killing someone– we have the right to allow parts of our history to become inactive, to fade. No one wants to spend their lives answering questions about an ill-considered remark in a bar, or an unfortunate relationship we had in college. We regularly negotiate with others over which parts of our past get retired (as Homer Simpson once pleased to Marge, "But honey, that was an empty promise!"), and which parts we continue to use to define us.

But as anyone who has had an angry comment on a Usenet group come back and haunt them knows, it's harder to get away from your past today. On the Internet, not only does everybody know that you're a dog (despite the great New Yorker cartoon), they know that you flamed flea collar manufacturers three years ago, and once argued that dog treats are a conspiracy to generate .

The problem is that computer memory and human memory are profoundly different. An essential part of human memory is its ability to creatively forget, and its capacity to rework the past. Letting go of some history is is prerequisite for moving beyond it. In contrast, computers aren't supposed to forget, and can't creatively mis-remember. If they do either one, the results are catastrophic.

And here technology doesn't provide us with a set of choices about how to design or implement devices– the option to have or deploy technologies that are more or less intrusive or invasive– but instead gives us a basic problem to be managed. For even though there have been some very interesting experiments in designing digital systems that do forget things over time, the virtues of perfect digital recall so dramatically outweigh the disadvantages as to make having forgetful computers an impossibility. Who would want computers that lose track of our bank balances?

As we conduct more of our lives online, as we leave more traces of ourselves in the digital world, and as others record more about us, freedom from our past is likely to become more elusive, and eventually a thing of the past. Maybe those baby blogs are a bit of a threat after all.

Still, I'm not going to give mine up. Instead, I'm keeping the password protection on, and the bots away; and when the kids turn sixteen, I'm going to turn the blog over to them. They can fold it into their own blogs if they want, they can put it on a shelf, or they can erase it. After all, it's their lives.

But I'm going to keep a copy. It's my life, too.