A facial recognition app that can work out the identities of strangers in a crowd by matching their faces with profiles on social media is taking Russia by storm.

In just two months FindFace has gathered 500,000 users who have run nearly 3 million searches, according to its founders.

The technology gained international attention when a photographer used it to create an art project that revealed just how much information strangers can gather about you with a picture of your face.

Russian photographer Egor Tsevtkov wanted to know how much personal data he could find out about complete strangers on the underground. With this idea in mind he photographed a selection of strangers, and used a free facial recognition software with terrifying results.

The software he used is a website called Find Face, which lets users look up people online using a photo, and accurately matches them up with a Facebook profile, based on their faces.

"I learnt a lot about a person's life without any contact," said Tsevtkov. "I felt slightly uncomfortable."

What he found

"I photographed people who were sitting in front of me in the subway, and then looked for them in social networks using open source software," said Tsevtkov, who called the resulting project called "Your face is Big Data".