Computers & Internet: how much does your computer tell others about you Have you ever had the feeling your computer is watching you? That somehow it knows what you were looking at yesterday, or last year? And that rather than being your technological ‘friend’ it behaves more like a slick second-hand car salesman? You fancied flying to Paris so you checked out airfares . . . and before you knew it, your Facebook page was plastered with advertisements for hotels on La Rive Gauche. Your daughter bought a record by One Direction. Now, the family computer is bombarded with ads for boy band concerts. It is all because of something on your computer called a ‘cookie’. The origins of their name are unclear, but cookies are vital to the running of the internet. When you visit a website, that site places a unique cookie on your computer so it recognises you when you come back. It allows the website to remember your login details and other pieces of information to save you enter...