It sounds like the premise of a dystopian sci-fi movie, but people in Russia are going nuts for an app that lets them take a photo of a stranger on the street, upload it to an app, and figure out their identity, with around 70 percent reliability.

If that’s making you feel mighty nervous, it should - imagine sitting on a train and the guy opposite you is checking out your LinkedIn profile. The guy behind you has already found your Facebook page and is now cyberstalking your best friend. The girl next to you has found you on Tinder.

Creepy for a whole different reason is the way the app can also be used in reverse - upload a photo of your celebrity crush, and it will bring up a bunch of strangers nearby who look like them.

Meet FindFace, a face recognition app developed by Russian 20-somethings Artem Kukharenko and Alexander Kabakov.

As ComputerWorld reports, the pair recently "upstaged" over 100 other facial recognition algorithms - including Google's - in the University of Washington’s MegaFace challenge by achieving a 73.3 percent accuracy on 1 million faces.

Since it launched two months ago in Russia, Findface has already racked up 500,000 users and processed nearly 3 million searches," according to Shaun Walker at The Guardian. It syncs up with Vkontakte - a popular social network in Russia and the former Soviet Union, which boasts more than 200 million accounts and nearly 1 billion photos.

"Three million searches in a database of nearly 1 billion photographs: that’s hundreds of trillions of comparisons, and all on four normal servers," Kabakov told Walker. "With this algorithm, you can search through a billion photographs in less than a second from a normal computer."

Basically, all you need to do is sneakily photograph someone on the street, upload the pic, and the app with serve up what it thinks is the most likely match, and 10 'bonus' identities that look similar.

"If you see someone you like, you can photograph them, find their identity, and then send them a friend request," says Kabakov. "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."

*Throws computer out the window, sets fire to house, moves in with a family of beavers*

If you think creepy as hell dating strategies are the worst of it… nope. The Guardian reports that people have already used the app to find personal social media accounts of porn stars and harass them, and a photographer in St Petersburg has been taking photos of strangers in the metro and publishing them online with their identities - no permission required.

"One girl in the project texted me after the publication and said that it was a bad feeling when she saw herself … but she fully understood my idea," photographer Yegor Tsvetkov told Elena Cresci at The Guardian last month.

The pair behind FindFace insist that this is not the direction they really want their software to go in. The goal is for their software to help solve crimes by by identifying criminals on the street, and make them a crapload of money in the retail sector.

"Kabakov imagines a world where cameras fix you looking at, say, a stereo in a shop, the retailer finds your identity, and then targets you with marketing for stereos in the subsequent days," says Walker.

*Sets fire to beaver home, moves to Mars*

Fortunately, the app only works with Vkontakte, and something would have to dramatically change in Facebook’s data storage systems for it to be able to access any photos - even public ones - on there. So we’re safe for now. But the idea and the technology is out there now, it pains me to say it, but it’s only a matter of time.