[Guardian News & Media Ltd] - If the founders of a new face recognition app get their way, anonymity in public could soon be a thing of the past. FindFace, launched two months ago and currently taking Russia by storm, allows users to photograph people in a crowd and work out their identities, with 70% reliability.

It works by comparing photographs to profile pictures on Vkontakte, a social network popular in Russia and the former Soviet Union, with more than 200 million accounts. In future, the designers imagine a world where people walking past you on the street could find your social network profile by sneaking a photograph of you, and shops, advertisers and the police could pick your face out of crowds and track you down via social networks.

In the short time since the launch, Findface has amassed 500,000 users and processed nearly 3m searches, according to its founders, 26-year-old Artem Kukharenko, and 29-year-old Alexander Kabakov.

Kukharenko is a lanky, quietly spoken computer nerd who has come up with the algorithm that makes FindFace such an impressive piece of technology, while Kabakov is the garrulous money and marketing man, who does all of the talking when the pair meet the Guardian.

Unlike other face recognition technology, their algorithm allows quick searches in big data sets. “Three million searches in a database of nearly 1bn photographs: that’s hundreds of trillions of comparisons, and all on four normal servers. With this algorithm, you can search through a billion photographs in less than a second from a normal computer,” said Kabakov, during an interview at the company’s modest central Moscow office. The app will give you the most likely match to the face that is uploaded, as well as 10 people it thinks look similar.

Kabakov says the app could revolutionise dating: “If you see someone you like, you can photograph them, find their identity, and then send them a friend request.” The interaction doesn’t always have to involve the rather creepy opening gambit of clandestine street photography, he added: “It also looks for similar people. So you could just upload a photo of a movie star you like, or your ex, and then find 10 girls who look similar to her and send them messages.”

Some have sounded the alarm about the potentially disturbing implications. Already the app has been used by a St Petersburg photographer to snap and identify people on the city’s metro, as well as by online vigilantes to uncover the social media profiles of female porn actors and harass them.

...continue reading the rest of this great article here.