Machines are becoming alarmingly intelligent, smart enough to root out crime.

A group of Google engineers tasked with looking out for online fraud and ad spam noticed something strange recently: photos of cars for sale in China kept getting flagged — not by the humans, but by a search engine algorithm.

Scammers were posting images of cars they didn’t own, breaking into them and selling them for money. So, how did Google detect the con?

Russell Brandom of The Verge has the details:

The algorithm saw a pattern of quick buys from new accounts, tied together with larger and more subtle patterns, and deduced something was up. It’s not an airtight system: more than a few valid accounts have had their orders delayed while the team checked them out. But in this case, it was able to reach across continents to suss out a scheme its engineers had never even imagined. Cultural differences could fool the humans, but they couldn’t fool the machine.

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