Even if you don't state your ethnic background anywhere on LinkedIn or whether you are married with children, a scan of your photos and other people's photos featuring you will make it far easier to deduce.

Many retail stores have consumer trackers that study how long your eyes linger on one product, whether you follow it through by touch, and things that you buy. You can redesign things on a shelf, all by tracking such information.

There's a whole load of stuff in life that is worth documenting. You see it every day but don't even notice.

What do you think is the world's most recognisable container of information? It's the human face. We are constantly reading each other and responding.

I spend a lot of my time looking into people's bags and handbags - with their permission, of course.

Facial recognition software is already quite accurate in measuring unchanging and unique ratios between facial features that identify you as you. It's like a fingerprint.