OK, so we’ve all got social network accounts now. If it’s not Facebook, it’s MySpace or Bebo or Ning or whatever.

I’ve been making these points to friends for a while now in various discussions, yet the implications of mass shared personal data in years to come doesn’t seem to have been considered by many people at all. I often find people surprised by the ideas, which I think are very likely to become a reality.

I think it maybe because we’re too used to thinking in block of five years when it come to the internet. Also, I’m not talking about the scary aspects of a Big Brother society (we hear them lot) but some of the benefits to be encountered in years to come, especially by future generations.

For example, we all know the popular Friends Reunited website. A place where you can rediscover lost relatives, classmates and streetmates was probably the once most-popular social networking tool. The Friends Reunited idea was great and today’s “2.0” social network tools have built on this.

But over the next few decades Friends Reunited will become completely redundant. I’m not saying the company will necessarily disappear down the pan, they will probably evolve to avoid disaster, but there is one crucial ongoing change that is sealing the fate of this service.

We are now forging maps of all our relationships way before they have a chance to be forgotten or be disconnected. In fifty years time, no one will need to use a reuniting service to find long-lost friends, instead you will just be able to look them up. Even if you forget their name, a few minor details (a year or an event you both attended) will give search tools enough to locate the person in your records. And even if you never added them as a ‘friend’, one of your friends may have done, so you search their records instead.

The social network is creating an incredibly rich layer of information that will eventually be available to our children and our children’s children. At the moment, if I want to find out the occupation, location and children of my great, great, great, great grandfather I know I can. I go to the census records and search, but this is probably the limit of what I can discover.

Essentially, I can track down some specific information about maybe the past six generations, in periods of every ten years for 167 years (since the national census began). If I want to go back further, it’s really sketchy. All I can ever know about any one of my blood ancestors is the house they were staying in on one particular night on maybe six or seven days of their whole life.

I cannot see a photo of them. I do not know who they knew or who they worked for. I do not know what their job entailed or where they travelled to. I maybe able to trace their accommodation if the buildings still exist, but I can’t see it as it was as they lived. I have no idea of their personality, their likes and their dislikes.

In fact in comparison to what will be available to our descendants in a few decades time will be truly stunning. We have to remember, our data is a commodity, and is only ours until we die. After a while it becomes the property of whoever buys it. In thirty years time, we don’t know who will own Facebook. We don’t know if anyone will sell the database of millions of names (the holy grail for anyone in the illegal mass-marketing game) or make it public by accident. But we can assume that it will not be that long before demand to the access of records by historians will be huge.

In 100 years time, when most of us will be gone – our grand kids will be curious to find out what they can about granddad in his youth. There will be no stigma attached to accessing this information, as like copyright, or the archaeological excavation of an ancient grave – it eventually becomes part of the public domain.

The curious result will that the process of mapping family/interpersonal history will become far more complex than it is now, but also more accurate. Historians will be able to plot the exact movements (or at least much more than they ever could now) of any person part of a social network. Although the information is likely to be biased to some extent (as it is self-generated), it will mean they will know the equivalent of if one of your ancestors taught Shakespeare English, or if great-granddad really did punch the guy who went on to invent time-travel.

Of course, it’ll all be open to interpretation and all the silly stuff that goes along with it. Jokey relationship “descriptions” between people in Facebook will cause maximum confusion for historians, but at the same time, they will be able to partially rectify this by piecing together a personality using the other information available, such as who the person talked to, the mannerisms expressed in their comments and the places they photographed.

Bearing in mind that just in the past thousand years, there have been at around 30 generations of You, meaning that you know very, very little about the millions of relatives that eventually made you you. Had things continued as they have done for centuries before, when you eventually pass on, your entire life would be (if you’re lucky) summed up in a name between two dates – birth and death – with no record of what you we’re doing one afternoon in the summer of 2007.

I’m not sure if other people feel the same way, but there is something strange, but not necessarily unpleasant about your descendants knowing this much about you. For example, it is very possible that in two hundred years time, these exact words could be being read by a seventh-generation grandchild of mine.

Hello kiddo.

Odd eh?