I recently wondered about what it would be like to learn your own life by heart. Let me now wonder about what it would be like to publish the public details of your life. But first, let me explain what I mean with this convoluted expression.

There is remarkably little in the life of most people which is "really" private. For most of what you do, there is at least one other person who knows about it. Some of these people are family members or friends, and you trust them and expect them to respect your privacy. But others are people you don't know and trust: all the strangers who saw you someday at some place, the cashier who knows what you bought last time you went to the supermarket, and so on. These aren't the worst, and I'll even forget about them and assume in the rest of this post that all of them are trustworthy. The things which aren't trustworthy are the information systems run by organizations which you have no reason at all to trust: public transportation companies, phone companies, banks, the State, and, last but not least, your Internet provider and the websites you visit and services you use online. (Maybe you trust these organizations, but, personally, I don't think that trust can apply to juristic persons.)

Now, we don't give much thought about this, because we assume that all these organizations aren't actively working together to stalk us. But this way of thinking gives a false sense of security. These people are untrusted, so good security practices should force us to assume that they did the worst possible thing--namely, that they collaborated and shared all the info they had to draw all possible conclusions. This is not that far-fetched if you keep in mind that most of the organizations I mentionned would problably gladly hand over any information they have about you to the police if they were asked for it (and probably wouldn't insist much if due process were bypassed).

Hence the idea I wish to develop here: what if you wanted to distinguish the private part of your life (ie. the "very private", namely things that no one but you knows about, and the "sort-of private", namely things that no one but you and trusted people know about) and the public part of your life (ie. things that at least one untrusted party knows about), and, to help your brain make that distinction, you assumed the worst-case scenario and started publishing all the public details of your life... (The rationale being the following: if this information is public, you might as well tell it to everybody rather than offering it specifically to the big organization who got the info in the first place.)

A thought experiment such as this one makes you realise the sheer quantity of things in your life which are public according to the above definition. Roughly speaking, you could probably publish:

Important parts of your medical history

Because even though your doctor may have a legal obligation to keep this secret, and even though you might trust him, lots of information about social security, prescriptions and the like are probably going through some electronic system leading to an untrusted party.

Everything you buy with a debit card

Your bank knows everything about that.

Everything you say over the phone

The phone company can hear it all. 'nuff said.

Your current precise location, 24-7

If you carry a mobile phone, the phone company knows where you are at any point in time. CCTV can add some precision in public places. If you travel using public transportation, the public transportation company usually knows where you go; if you drive, beware of CCTV and toll roads.

Everything you do on the Internet

It is possible to communicate privately (in the strict sense defined above) over the Internet, using end-to-end encryption (that is, encryption and decryption are performed on the trusted users' machines, which should be running a secure and open-source OS). However, unless you know you're doing that, you probably aren't, and, when you're using the Internet, you're either using encryption to talk to an untrusted big organization like Google (and they know about what you do) or no encryption at all (and the Internet provider knows about what you do).

The amount of information available on the web today is so large that it is tempting to think of it as some kind of library of Babel in which you don't wonder if the information exists but if the information can be found reasonably easily.

To some extent, this is a good way to think about data in general. The web (and, more generally, the sheer amount of data we have to manage today) has forced us to realize that archiving things is not enough if the archives aren't easily accessible and searchable. It's all well and good to keep things, but there is a huge difference between an ordered collection with a nice interface which you will actually use, and a messy dead drop of data which you will never take the time to consult.

However, if there is indeed a difference between ordered data and messy data, there is also a huge difference between messy data and no data at all. The thing is that, in some cases, you just need a piece of data, and searching for it in a wide mess, however tedious, is the only possibility. Or think about a book by some obscure author. Even if the only copy is hidden deep in some mysterious library (or, for that matter, a nameless PDF amongst thousands of others on some website), this is still very different from no copy at all. The thing is that you never know what's going to happen in the future, and it is still possible that someday, somehow, somebody stumbles upon it.

(Here is a stupid way to think about it: losing the Ring at the bottom of a river isn't the same as destroying it for good. Of course, the Ring has a will of its own and can lure people towards itself, whereas data cannot really do this kind of thing, but you get the idea.)

This is why, in my opinion, it is a good idea to archive in bulk everything which could conceivably be useful someday but probably won't be, because sorting it out isn't worthwhile whereas having it around just in case you desperately need it can turn out to be a good thing.

Every now and then, you come across some text in which the author expresses things which, deep down, you just know to be correct. You feel as if someone was saying what you always wanted to say; sometimes, it is written more elegantly than you could ever hope to acheive.

Such texts are slightly useful, because they allow you to discover what it is that you believe.

Every now and then, you come across some text in which the author expresses things which, deep down, you just know to be plain wrong. You feel forced to refute every single sentence, don't always manage to do so, and you feel uncomfortable when the author, following some apparently sensible line of reasoning, managed to reach conclusions which are undoubtedly complete nonsense.

Such texts are quite useful, because they allow you to discover what it is that you believe and why you believe it, and because they sometimes force you to question and eventually change those beliefs. They may make you different, in the sense that you can look at your former self and realize how wrong you were.

Every now and then, you come across some text in which the author expresses things which are just weird. The text is just puzzling, because it is written in an unexpected way, about some unexpected thing, with an unexpected angle, or for an unexpected purpose. It seems as if the author is either crazy or not living in the same universe as you.

Such texts are immensely useful, because they allow you to discover things and ways of thinking about things which you didn't even envision before. They allow you to discover the sheer diversity of human nature, and may suddenly and radically change your perspective about the world. They may make you different, in the sense that you can look at your former self and realize that, for some undefinable reason, you aren't the same person anymore.

When you design a cryptographic system, you don't say "Believe me, it's secure", but "I did everything I could to ensure that you don't need to trust me". See for instance the Stamper FAQ (an interesting service, by the way): It would be very easy for me to try and say what a reliable and trustworthy sort of a fellow I am [...]. This would not be good enough!!!

Compare with politics, in which candidates for any sort of political office are precisely trying to convince you that they are reliable and trustworthy... Imagine how it would be if there was a politician whose main electoral promise was total transparency to ensure that you don't need to trust him...

Microblogging services such as Identi.ca (the one I use) and Twitter (the one I avoid because it is uselessly centralized) have an interesting feature: when you have an account on them and choose to subscribe to someone's feed, that person knows that you are following them.

However, I fear that people may become accustomed to this feature, and may come to believe that they will always know who is following them. Of course, this isn't true: for the many users who publish their microblogging entries to everyone, people can just follow the RSS feed without even having an account on the microblogging platform you're using.

The bottom line is that it doesn't make much sense to ask somebody to stop following your feed. The content of the feed is most likely public, and they can just silently follow you. If the problem is that you do not want to advertise them in your followers list, it's your job to manage the list properly, and remove the people you don't like without having to ask them to leave.