Researchers from University of Berkeley and experts from Facebook's AI lab have developed a method known as Pose Invariant PErson Recognition or 'Piper'. Piper is capable of identifying individuals in various poses, including from the side, behind and .

Chances are there are hundreds, if not thousands, of images of you across the web that you don't even realise you are in.

If a stranger has taken a photo in a crowded place and you've been snapped in the background accidentally, you would be none the wiser.

An algorithm created by Facebook has the potential to scour the web for such pictures and warn a person about them. 

But the technology could also be used to more easily track people, and a privacy expert is calling for our faces to be protected in the same way our fingerprints and DNA are.

Currently, facial recognition requires a full frontal face to work most effectively. It scans for various markers in a photo to plot and match similar shapes.

As humans, we can recognise people from their profile, or the back of their head with ease and computer scientists are trying to build artificial intelligence that does the same.

http://www.dailymail.co.uk/sciencetech/article-3136191/Facebook-recognise-t-face-Piper-software-identifies-people-sides-head.html