The deep web content is estimated at close to 500 times that of the surface web, yet it has still remained mostly untapped due to the limitations of traditional search engines.
Such aggregation can be very powerful: combining the personal information from someone's Facebook profile with their employment history on LinkedIn and public documents (such as the electoral roll) via 192.com quickly uncovers more than enough data to be able to clone someone's identity.
Privacy's bleak future
Of course, you can always close your online accounts and hope that nobody has copied your sensitive data. Or can you? If you shut down a Facebook account, it actually remains on Facebook so that you can reactivate it if you change your mind at any time in the future.
Everything that you've posted on the service - messages, photo comments, status updates and so on - remains online unless you go to the trouble of manually deleting it all one by one.
So should we just accept privacy is dead and get over it?
"No!" says Theriault. "The roll over and die is not a good option, but I don't think people should get overly paranoid either. Common sense will save the day."
As Theriault points out, the problem is that people often provide information that isn't strictly necessary to participate in the service. Given that social networking sites allow you to send messages to your friends, "do you really need to offer up your mobile number, instant messaging information and email address when you're connecting with people you already know?
"Do you need your full date of birth? Do you need to give away your entire work and education history?"
Theriault's message to social network users is simple: "Ask yourself - should I be posting this amount of information?"
When you consider all the ways in which your personal data could be used against you and the possibility that it may all hang around to haunt you forever, more often than not the answer should be a very simple no.
The full version of this article can be read in the November 2007 issue of PC Plus magazine, currently on sale.
