A great insight from Mikko Hypponen on what Twitter knows about you and how. And Facebook does a similar thing. At the very least so they can target advertising. Mikko is always worth listening to – and you may like to know how you are being tracked.
And whilst I’m on the subject, Kevin Mitnick shows just how easy it is for you, your personal details and your bank accounts can be hacked. You might want to revisit your on-line security.