Facial recognition technology is a pretty amazing thing. It can be used in a variety of applications, from identifying Uber drivers, to tagging friends on Facebook, to paying for goods on Amazon (eventually). Now, its use has inevitably spread to that most common of internet pastimes: porn.

Belgian site Megacams.me, which calls itself a “live sex search engine,” has introduced what’s claimed to be the first ever “sex doppelgänger” feature. It involves desperate customers sending in a photo of a fantasy partner – co-worker, movie star, unsuspecting neighbor – and the software finding a camgirl from the 180,000 available who looks like the person in the picture.

“This way,” says Megacams, “it feels like you are having live sex with the person in your picture.” The system requires a front on photograph of the subject - not easy when you're taking it from a bush 20 feet away.

TechCrunch tested the system and the best match it found was rated at just 47 percent likeness. So you may have to squint a bit to feel like you’re interacting with the secret object of your affections/stalking target.

Considering how it’s being used, Megacams isn’t willing to reveal which facial recognition software is powering the process, though TechCrunch believes it to be Microsoft’s Cognitive Services. Formerly called Project Oxford, the technology appears in the Redmond firm’s popular “Guess your age” and “Guess your emotion” tools.

Microsoft’s API gives developers 30,000 free searches a month, after that it’s $1.50 for every 1000 lookups.

Megacams denied that the feature was creepy. "People are watching their girl next door all the time," spokesperson Eddy L told The Verge. "If they don't use this tool they click and click forever until they find the doppelgänger in porn. We just give them the tools right now to make that search easier."

The site says that uploaded photos are deleted as soon as the search has been performed.

Facial recognition technology may offer amazing ways to enhance out lives but, like the Russian privacy nightmare FindFace, most people would agree that this isn’t one of them.